Every compound in the library
177 compounds, listed alphabetically. Each entry states what the compound is, what it is commonly said to be good for, and what the published research shows. Entries are added continuously; a missing compound is one the library has not reached yet.
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5-Amino-1MQ
Not a peptide · Small molecule
5-Amino-1MQ is a small-molecule NNMT inhibitor, not a peptide. What NNMT does, what the mouse and cell studies found, and how little of it is in humans.
Last checked 2026-09-07
A
Abaloparatide (Tymlos)
FDA-approved (2017) · 34 amino acids; molecular weight 3,961 daltons (Tymlos label)
Abaloparatide (Tymlos) is a 34-amino-acid copy of parathyroid hormone-related peptide with one unnatural amino acid. Approved in 2017 for postmenopausal osteoporosis and later for men, it builds bone rather than slowing its loss. In its pivotal trial new spine fractures fell from 4.2% to 0.6% over 18 months.
Last checked 2026-09-28
ACTH (adrenocorticotropic hormone, corticotropin)
Made by the body · 39 amino acids, a straight chain with no disulfide bonds
ACTH (adrenocorticotropic hormone, corticotropin) is a 39-amino-acid hormone from the pituitary gland that tells the adrenal glands to make cortisol. It is cut from the same precursor as the melanocyte-stimulating hormones and beta-endorphin. It is sold as porcine gels for infantile spasms and inflammatory flares, and its first 24 amino acids, cosyntropin, are the standard adrenal test.
Last checked 2026-10-03
Adiponectin (Acrp30, apM1; the product of the ADIPOQ gene)
Made by the body · 226 amino acids once its 18-residue signal sequence is removed, circulating as trimers and larger assemblies — more than five times the 40-residue line US regulation uses for proteins (UniProt Q15848; 21 CFR 600.3)
Adiponectin is a 226-amino-acid hormone made almost only by fat cells, and its blood level is lower, not higher, in people with obesity. What it is, what it is described as doing, what the test is used for, and why no adiponectin medicine exists.
Last checked 2026-10-27
Adipotide (FTPP, prohibitin-targeting peptide, Prohibitin-TP01)
Peptide · A short targeting sequence joined to a cell-killing sequence
Adipotide is a fat-targeting peptide sold for weight loss. Searching the trial registry for that name returns nothing — its single human trial is filed as Prohibitin Targeting Peptide 1, and it was stopped with four participants enrolled.
Last checked 2026-09-13
AHK-Cu (L-alanyl-L-histidyl-L-lysine copper(II); tripeptide-copper complex)
Not approved as a medicine · 3 amino acids, plus one copper ion
AHK-Cu is alanine–histidine–lysine bound to copper, a close cousin of GHK-Cu. Its hair-growth reputation rests on one 2007 study of hair follicles in a dish; no human trial of it has been published.
Last checked 2026-10-28
AICAR (acadesine, AICA riboside)
Not a peptide · Not applicable — a nucleoside, not a chain of amino acids
AICAR has one of the largest human records of any compound in this library — a 3,080-patient phase 3 trial among them. Every one of those studies was about heart surgery or leukaemia, and the big one was stopped for futility.
Last checked 2026-09-11
Amlexanox
Not a peptide — a small molecule · Not applicable: a small molecule, C16H14N2O4, molecular weight 298.29
Amlexanox is a small molecule, not a peptide, first approved in the US as a 5% paste for mouth ulcers. Both US products are now discontinued. Its repurposing for type 2 diabetes rests on one 42-person trial: HbA1c fell modestly, while body weight fell further on placebo than on the drug.
Last checked 2026-09-21
Amylin (islet amyloid polypeptide, IAPP)
Made by the body · 37 amino acids, with a disulfide bond between the cysteines at positions 2 and 7 and an amidated tyrosine at the end
Amylin is a 37-amino-acid hormone that pancreatic beta cells release together with insulin. It slows stomach emptying, damps the glucagon surge after meals and signals fullness. It was found in 1987 in the amyloid deposits of type 2 diabetic pancreases. Human amylin itself clumps, so every amylin medicine is an altered copy.
Last checked 2026-10-02
Amyloid-beta (Aβ, beta-amyloid; Aβ40 and Aβ42)
Made by the body · Mainly 40 or 42 amino acids (Aβ40 and Aβ42), depending on where the final cut falls
Amyloid-beta is a peptide of 40 or 42 amino acids cut from a much larger brain protein, APP. It clumps into the plaques found in Alzheimer's disease and was first purified in 1984. The approved Alzheimer's drugs that target it are antibodies, not peptides; the largest trial showed moderately slower decline with brain-swelling side effects.
Last checked 2026-10-04
Angiotensin (angiotensin I, angiotensin II and their fragments)
Made by the body · Angiotensin I is 10 amino acids; angiotensin II is 8; angiotensin 1–7 is 7; angiotensin III and IV are shorter still
Angiotensin is a family of short peptides cut from angiotensinogen: angiotensin I (10 amino acids), angiotensin II (8) and smaller fragments. Angiotensin II constricts blood vessels and releases aldosterone. Synthetic angiotensin II (Giapreza) was approved in 2017 for shock after a 321-patient trial.
Last checked 2026-10-04
AOD-9604 (also sold as HGH fragment 176-191)
Synthetic fragment analogue · About 16 amino acids
AOD-9604 is a piece of growth hormone, sold for fat loss. Its research file holds 22 papers — seven of them about how anti-doping laboratories find it in urine, and none a human trial.
Last checked 2026-09-10
Apitegromab (SRK-015)
Not a peptide — a monoclonal antibody · Not applicable in the peptide sense: a full-size human IgG antibody
Apitegromab is a monoclonal antibody, not a peptide, that blocks myostatin before it activates. Its phase 3 in spinal muscular atrophy met its endpoint on the combined dose and missed it on the 20 mg/kg dose alone. A separate trial with tirzepatide preserved 1.9 kg of lean mass.
Last checked 2026-09-20
ARA-290 (cibinetide)
Peptide · 11 amino acids
ARA-290 has what almost nothing else in this library has — a randomized, placebo-controlled, quadruple-masked phase 2 with posted results. Reading those results is the point: the middle dose beat the highest, and on one nerve measure placebo beat all three.
Last checked 2026-09-13
Argireline
Cosmetic ingredient · Hexapeptide (6 amino acids)
Argireline is acetyl hexapeptide-8, sold in wrinkle creams as a topical alternative to botulinum toxin. What it is, what the registered trials actually studied, and how thin the cosmetic evidence is.
Last checked 2026-09-08
Atrial natriuretic peptide (ANP, atriopeptin)
The body's own hormone · 28 amino acids, with a 17-residue ring closed by one disulfide bond (UniProt P01160)
Atrial natriuretic peptide (ANP) is a 28-amino-acid hormone released by the heart's upper chambers when they are stretched. It makes the kidneys excrete salt and water and widens blood vessels. Its sequence, its family, the 1981 discovery, and carperitide, the ANP drug used in Japan.
Last checked 2026-10-17
B
B7-33 (single-chain relaxin-2 B-chain analogue)
Preclinical only · A single linear chain named for residues 7 to 33 of relaxin-2's B chain
B7-33 is a short synthetic piece of the hormone relaxin-2, designed in Melbourne in 2016 to keep relaxin's anti-scarring effect while dropping the signal linked to tumour growth. PubMed holds eleven records, none in people; the trial registry holds none. The full hormone it comes from failed a 6,545-patient heart failure trial.
Last checked 2026-09-23
Bacitracin (as bacitracin or bacitracin zinc; mainly bacitracin A)
Over-the-counter first-aid antibiotic (US monograph) · Bacitracin A, the main component: a cyclic peptide — a thiazoline-containing first unit followed by a chain of amino acids, partly closed into a ring; C66H103N17O16S, molecular weight 1,422.7 (PubChem CID 10909430, ChEBI)
Bacitracin is a mixture of related cyclic peptides, mainly bacitracin A, a looped peptide made by a Bacillus bacterium. It is sold over the counter as a first-aid antibiotic ointment and on prescription in eye ointments. The injectable form was withdrawn in 2020 after FDA judged its kidney and allergy risks outweighed its benefit.
Last checked 2026-10-11
Bimagrumab (BYM338, LY3985863)
Not a peptide — a monoclonal antibody · Not applicable in the peptide sense: a full-size IgG antibody of roughly 1,300 amino acids across four chains
Bimagrumab is a monoclonal antibody, not a peptide, that blocks the activin type II receptors limiting muscle growth. It missed its endpoint in a muscle-wasting disease, then returned in obesity trials beside semaglutide and tirzepatide. What it is and what the trials show.
Last checked 2026-09-17
Bivalirudin (Angiomax, Angiomax RTU, and generics)
FDA-approved (2000) · 20 amino acids; molecular weight 2,180 (anhydrous free base, label); C98H138N24O33 (PubChem CID 16129704)
Bivalirudin is a synthetic 20-amino-acid peptide that blocks thrombin directly, used by vein during coronary angioplasty and stenting, including in people who cannot have heparin. Its tail borrows from hirudin, the leech anticoagulant. Its sequence, why it wears off in about 25 minutes, the trials behind it and its US status.
Last checked 2026-10-26
Bleomycin
FDA-approved (since 1973) · Not a single molecule: a mixture whose main component, bleomycin A2, is C55H84N17O21S3+, 1,415.6 Da (PubChem CID 5460769)
Bleomycin is a mixture of glycopeptide antibiotics made by the soil bacterium Streptomyces verticillus, used since 1973 as cancer chemotherapy for testicular cancer, lymphomas and squamous-cell cancers. It is dosed in units, not milligrams. What it is, how it damages DNA, and the lung toxicity that defines its label.
Last checked 2026-10-22
BNP and NT-proBNP (B-type natriuretic peptide and its N-terminal fragment)
A human hormone, not a sold compound · BNP-32 is 32 amino acids. NT-proBNP is 76. They are the two halves of one 108-residue prohormone.
A 108-residue prohormone splits into two fragments — NT-proBNP at 76 residues and BNP at 32. One is cleared by an enzyme, the other is not, which is why a common heart-failure drug pushes the two tests in opposite directions.
Last checked 2026-09-19
Bortezomib (Velcade; generics)
FDA-approved (since 2003) · 2 amino-acid units — phenylalanine and a leucine analogue — capped with a pyrazine ring; C19H25BN4O4, molecular weight 384.24 (label)
Bortezomib, sold first as Velcade, is a modified dipeptide: phenylalanine and a leucine analogue whose end carries boronic acid instead of a carboxyl group. It blocks the proteasome, the cell's protein-shredding machine, and is approved for multiple myeloma and mantle cell lymphoma. Its structure, trial results and the nerve-damage warning that changed how it is given.
Last checked 2026-10-14
BPC-157
Not approved anywhere · 15 amino acids
BPC-157 is a 15-amino-acid peptide from a gastric protein fragment. The healing claims, where they come from, why almost all of them are rodent studies, and its current FDA compounding status.
Last checked 2026-09-22
Bradykinin (BK); its ten-amino-acid form is kallidin (lysyl-bradykinin)
Made by the body · 9 amino acids; kallidin is the same chain with one extra lysine at the front (10)
Bradykinin is a nine-amino-acid peptide cut from a blood protein, kininogen, when tissue is injured or inflamed. It widens blood vessels, makes them leaky and triggers pain. It was named in 1949 after it appeared when snake venom was added to blood plasma. No medicine is bradykinin itself; the approved drugs block it or slow its breakdown.
Last checked 2026-10-02
C
C-peptide (connecting peptide)
A laboratory measurement, not a product · 31 amino acids
C-peptide is the 31-residue piece cut out and discarded when the body makes insulin. It is the most-studied peptide in this library and the only one nobody sells — because its entire value is as a measurement.
Last checked 2026-09-16
Cagrilintide
Not approved alone · Amylin analogue
Cagrilintide is a long-acting amylin analogue tested with semaglutide as CagriSema. What the REDEFINE phase 3 trials reported, and what it is not approved for on its own.
Last checked 2026-09-07
CagriSema (cagrilintide + semaglutide)
Not approved (Drugs@FDA, 2026-10-22) · Two peptides: cagrilintide C194H312N54O59S2, 4,409 Da (PubChem CID 171397054), and semaglutide, a 31-residue GLP-1 analogue
CagriSema is not one molecule but two peptides given together once a week: cagrilintide, a long-acting amylin analogue, and semaglutide, the GLP-1 drug in Wegovy and Ozempic, at 2.4 mg each. It is not approved. What each part is, what the two phase 3 REDEFINE trials found, and what they did not test.
Last checked 2026-10-22
Calcitonin (human hormone); calcitonin salmon (the medicine)
Made by the body · 32 amino acids, with a ring closed by a disulfide bond between positions 1 and 7 and an amidated proline at the end
Calcitonin is a 32-amino-acid hormone made by the thyroid's C cells that briefly lowers blood calcium. The medicine is salmon calcitonin, which differs from the human hormone at 16 of 32 positions. It is approved for Paget's disease, hypercalcaemia and postmenopausal osteoporosis, with fracture reduction not demonstrated and a malignancy warning.
Last checked 2026-10-05
Calcitonin gene-related peptide (CGRP; α-CGRP / CGRP1 from the CALCA gene, β-CGRP / CGRP2 from CALCB)
Made by the body · 37 amino acids, with one disulfide bond between the cysteines at positions 2 and 7 and an amidated phenylalanine at the end (UniProt P06881, P10092)
Calcitonin gene-related peptide (CGRP) is a 37-amino-acid peptide made mainly in nerve tissue that widens blood vessels. It comes from the same gene as the thyroid hormone calcitonin, cut a different way. Eight FDA-approved migraine drugs block it or its receptor; CGRP itself is not a medicine.
Last checked 2026-10-06
Capromorelin (as capromorelin tartrate; Entyce for dogs, Elura for cats)
Not a peptide (small molecule) · Not an amino-acid chain: a single synthetic molecule, C28H35N5O4, molecular weight 505.6 (PubChem CID 216208); sold as the tartrate salt, C28H35N5O4·C4H6O6, molecular weight 655.70 (Entyce label)
Capromorelin is a small-molecule ghrelin-receptor agonist approved in the US for dogs (Entyce, 2016) and for weight loss in cats with kidney disease (Elura, 2020). It mimics the gut hormone ghrelin but is not itself a peptide, and both labels say it is not for use in humans.
Last checked 2026-11-03
Carfilzomib (Kyprolis)
FDA-approved (since 2012) · 4 amino-acid units with a morpholine cap and an epoxyketone end; C40H57N5O7, molecular weight 719.9 (label)
Carfilzomib, sold as Kyprolis, is a tetrapeptide epoxyketone: a chain of four amino-acid units ending in a reactive epoxide that binds the proteasome irreversibly. It is approved for relapsed or refractory multiple myeloma, alone or with other drugs. Its structure, its two pivotal trials and the heart warning on its label.
Last checked 2026-10-14
Cartalax (AED, Ala-Glu-Asp)
Peptide · 3 amino acids
Cartalax is a three-amino-acid peptide from the Russian bioregulator tradition. Its entire published record is six papers, every one of them cell culture — and the trial registry has never held a single entry for it.
Last checked 2026-09-11
Casein phosphopeptide (CPP; as CPP-ACP, casein phosphopeptide–amorphous calcium phosphate; trade name RECALDENT)
Made from milk protein · A family of short peptides, not one molecule: fragments released from milk caseins by enzyme digestion that keep the casein's clusters of phosphorylated serine and other acidic residues (Cochrane and Reynolds 2012, PMID 22899678)
Casein phosphopeptides are short fragments cut from milk casein that carry clusters of phosphorylated serine. Bound to calcium phosphate as CPP-ACP (trade name Recaldent), they are the active ingredient in dental pastes such as MI Paste. A 2024 meta-analysis found adding CPP-ACP to fluoride no better than fluoride alone for early white-spot lesions.
Last checked 2026-11-03
Cerebrolysin
Not approved in the US · A mixture, not one molecule
Cerebrolysin is a peptide preparation made from enzymatically broken-down porcine brain protein. Widely used in some countries, unapproved in the US — and what the Cochrane reviews concluded.
Last checked 2026-09-07
Cholecystokinin (CCK; main forms CCK-58, CCK-33 and CCK-8; synthetic CCK-8 = sincalide, Kinevac)
Made by the body · Cut from a 115-residue precursor into CCK-58, -39, -33, -25, -18, -12, -8, -7 and -5 (UniProt P06307). Sincalide, the approved drug, is the 8-residue C-terminal fragment
Cholecystokinin (CCK) is a peptide hormone released in the small intestine after a meal. It makes the gallbladder contract and the pancreas release digestive enzymes. It circulates in several lengths cut from one precursor, shares its last five amino acids with gastrin, and its eight-amino-acid tip is made synthetically as sincalide, a diagnostic injection.
Last checked 2026-10-11
Chromogranin A (CgA; the product of the CHGA gene)
Made by the body · 439 amino acids once its 18-residue signal sequence is removed — about eleven times the 40-residue line US regulation uses for proteins (UniProt P10645; 21 CFR 600.3). Its fragments range from 8 to 113 residues.
Chromogranin A is a 439-amino-acid protein stored in the hormone granules of nerve and endocrine cells, and the parent of a family of smaller peptides. What it is, what its fragments are described as doing, and why its blood test, used to follow neuroendocrine tumours, rises for other reasons too.
Last checked 2026-10-27
CJC-1295
Not approved anywhere · GHRH analogue, 30 amino acids
CJC-1295 with DAC has a half-life of days; CJC-1295 without DAC is modified GRF 1-29 and lasts minutes. Vendors sell both under one name. The difference is enormous.
Last checked 2026-09-07
Colistin (polymyxin E; injected as colistimethate sodium, also called colistin methanesulfonate)
FDA-approved (since 1962) · A cyclic peptide with a fatty-acid tail; colistin A is C52H98N16O13, molecular weight 1,155.4 (PubChem CID 5311054)
Colistin is polymyxin E, a ring-shaped peptide antibiotic with a fatty tail made by Bacillus polymyxa. Injected, it is given as colistimethate sodium, an inactive prodrug. It is kept for Gram-negative infections nothing newer can treat, its label warns of kidney and nerve toxicity, and a transferable resistance gene found in 2015 put it in the news.
Last checked 2026-10-26
Collagen peptides (hydrolysed collagen, collagen hydrolysate; gelatin hydrolysate)
A mixture of peptides, not one compound · Variable — a mixture of fragments of different lengths cut from collagen chains. The parent chain is long: the human collagen I alpha-1 chain is 1,057 residues after its propeptides are removed (UniProt P02452)
Collagen peptides are fragments made by cutting collagen — the body's main structural protein — with enzymes, usually from cow or pig hide, bone or fish skin. They are a mixture, not one compound. What the collagen chain is made of, what the gut absorbs (mostly Pro-Hyp), how it is regulated as food, and how large the trial record is.
Last checked 2026-10-20
Corticotropin-releasing hormone (CRH; corticotropin-releasing factor, CRF; corticoliberin)
Made by the body · 41 amino acids, with an amidated isoleucine at the end — residues 154–194 of a 196-residue precursor (UniProt P06850)
Corticotropin-releasing hormone (CRH, also called CRF) is a 41-amino-acid hormone from the hypothalamus that tells the pituitary to release ACTH, which in turn drives cortisol. It is not ACTH and not cortisol. A sheep version, Acthrel, is approved only as a diagnostic in Cushing's work-ups, and a drug that blocks one of its receptors was approved in 2024.
Last checked 2026-10-06
Cosyntropin (Cortrosyn; also generic cosyntropin) — synthetic ACTH(1-24), tetracosactide outside the US
FDA-approved (since 1970) · 24 amino acids in an open chain — the first 24 of ACTH's 39; molecular weight 2,934 g/mol, formula C136H210N40O31S (Cortrosyn label)
Cosyntropin (Cortrosyn) is a synthetic peptide made of the first 24 of ACTH's 39 amino acids. It is not a treatment: it is injected once, and blood cortisol is measured 30 and 60 minutes later to screen for adrenal insufficiency. The label sets the cut-off and lists the medicines that can make the result wrong.
Last checked 2026-10-05
Cyclic citrullinated peptide (CCP) — the antigen in the anti-CCP antibody test
A laboratory reagent, not a product · A short synthetic peptide; the exact sequences used in commercial assays are the manufacturers' own
A cyclic citrullinated peptide is a synthetic, ring-shaped peptide carrying the amino acid citrulline. Nobody takes it: it is the bait in the anti-CCP blood test, which looks for antibodies against it. A 2007 meta-analysis of 37 studies put the test's pooled specificity for rheumatoid arthritis at 95% and its sensitivity at 67%.
Last checked 2026-09-30
Cyclosporine (ciclosporin, cyclosporin A; Sandimmune, Neoral, Gengraf, Restasis and others)
FDA-approved (since 1983) · 11 amino acids in a closed ring; 7 of the 11 are N-methylated (our count from the label's chemical name)
Cyclosporine (ciclosporin, cyclosporin A) is a cyclic peptide of 11 amino acids made by a fungus, seven of them N-methylated. It suppresses the immune system by blocking calcineurin and is approved to prevent organ-transplant rejection, for severe psoriasis and rheumatoid arthritis, and as eye drops for dry eye. Its structure, its approvals and the boxed warnings on its labels.
Last checked 2026-10-14
D
Dalbavancin (Dalvance; generic dalbavancin hydrochloride)
FDA-approved (since 2014) · A heptapeptide core — seven amino acids, the core common to all glycopeptide antibiotics (Zhanel 2010, PMID 20426497) — carrying sugars and a fatty acid chain. The drug is a mixture of five closely related forms; the main one, B0, weighs 1,816.7 (label)
Dalbavancin (Dalvance) is a lipoglycopeptide antibiotic: a core of seven amino acids, shared with vancomycin's class, plus sugars and a fatty side chain. It blocks the last step of bacterial cell-wall building. Its half-life is long enough that a whole course for a skin infection is one or two infusions a week apart. Generic versions reached the US market from late 2025.
Last checked 2026-10-06
Daptomycin (originally Cubicin; now generic)
FDA-approved (since 2003) · 13 amino acids with a decanoyl (10-carbon fatty acid) tail; C72H101N17O26, molecular weight 1,620.67 (label)
Daptomycin is a cyclic lipopeptide antibiotic: thirteen amino acids, ten of them closed into a ring, with a fatty-acid tail, made by the soil bacterium Streptomyces roseosporus. It is given intravenously for complicated skin infections and Staphylococcus aureus bloodstream infections. Its label rules out pneumonia and warns about muscle damage.
Last checked 2026-10-11
Degarelix acetate (Firmagon)
FDA-approved (since 2008) · 10 amino acids in a straight chain (a linear decapeptide amide), seven of them unnatural and five of those mirror-image D-forms; molecular weight 1,632.3 Da (label)
Degarelix (Firmagon) is a ten-amino-acid peptide, seven of them non-natural, that blocks the pituitary's GnRH receptor and lowers testosterone in men with advanced prostate cancer. In its pivotal trial 96% reached castration levels by day 3, against 0% on leuprolide, which first pushes testosterone up.
Last checked 2026-10-05
Dermorphin (H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2)
Not approved anywhere · 7 amino acids (a heptapeptide), C-terminal amide
Dermorphin is a seven-amino-acid opioid peptide from the skin of South American Phyllomedusa frogs, unusual for carrying a D-amino acid. It was never developed into a medicine and is best known today as a racehorse doping agent.
Last checked 2026-10-28
Desmopressin acetate (DDAVP; 1-desamino-8-D-arginine vasopressin)
FDA-approved (since 1978) · 9 amino acids — the same length as the natural hormone vasopressin
Desmopressin (DDAVP) is a synthetic copy of the hormone vasopressin with two changes that make it last longer and act mostly on the kidney. It is one of the few peptide drugs sold as a tablet, even though only about 0.16% of a swallowed dose reaches the blood compared with an injection. Every US nasal-spray brand is now discontinued; a new oral solution was approved in 2026.
Last checked 2026-09-23
Dihexa
Not approved anywhere · Small peptide derivative
Dihexa is an angiotensin IV-derived compound developed to act on the hepatocyte growth factor system. Striking preclinical potency claims — and nothing in people.
Last checked 2026-09-07
Dotatate (DOTA-Tyr3-octreotate)
FDA-approved (scan since 2016, treatment since 2018) · 8 amino acids, cyclic, one disulfide bond; dotatate itself 1,435.6 Da (NETSPOT label)
Dotatate is an eight-amino-acid ring peptide, a close relative of octreotide, with a chemical cage that holds a radioactive metal. With gallium-68 or copper-64 it is a PET scan for neuroendocrine tumours; with lutetium-177 it is Lutathera, the treatment called PRRT. Sequence, the trials, the warnings.
Last checked 2026-10-17
DSIP
Not approved anywhere · 9 amino acids
Delta sleep-inducing peptide was isolated in the 1970s from sleeping rabbits. Nearly fifty years later it is still unapproved and still thinly evidenced. Why that matters.
Last checked 2026-09-07
Dulaglutide (Trulicity)
FDA-approved (since 2014) · Two identical chains, each a 31-amino-acid GLP-1 analogue joined by a short peptide linker to a modified IgG4 antibody Fc fragment; about 63 kilodaltons in total
Dulaglutide (Trulicity) is a once-weekly GLP-1 drug for type 2 diabetes. Strictly it is not a small peptide: two copies of a GLP-1 analogue are fused to part of an antibody, giving a 63-kilodalton molecule with a five-day half-life. Its label, its heart-outcomes trial and what is known, entry by entry.
Last checked 2026-09-27
E
Echinocandins (caspofungin, micafungin, anidulafungin, rezafungin)
A drug class, not one drug · Each is a cyclic hexapeptide — six amino acids closed into a ring — carrying a fatty side chain; the labels call them semisynthetic lipopeptides (micafungin: ChEBI via PubChem CID 477468)
Echinocandins are antifungal medicines built on a ring of six amino acids with a fatty tail. They block a fungal cell-wall sugar that human cells do not make. Four are approved in the US: caspofungin (2001), micafungin (2005), anidulafungin (2006) and the once-weekly rezafungin (2023).
Last checked 2026-11-03
Ecnoglutide (XW003; oral form XW004, also VRB-101)
Approved in China (2026) · A modified GLP-1 peptide analogue, given once weekly
Ecnoglutide is a once-weekly GLP-1 peptide analogue from Sciwind Biosciences, engineered to favour one signalling route over another. China approved it for type 2 diabetes in January 2026 and for weight management in March 2026. Every phase 3 trial behind it was run in China, and the US drug database has no entry.
Last checked 2026-09-21
Eloralintide (LY3841136)
Not approved anywhere · A long-acting peptide analogue of amylin; the sources opened for this entry do not give its full sequence
Eloralintide (LY3841136) is Eli Lilly's once-weekly amylin receptor agonist for obesity, built to prefer one amylin receptor over the calcitonin receptor. Its 48-week phase 2 trial reported 9% to 20% weight loss against 0.4% on placebo. It is not approved anywhere. What it is and what the record holds.
Last checked 2026-09-27
Enkephalins (Met-enkephalin and Leu-enkephalin; Met-enkephalin is also studied as 'opioid growth factor')
Made by the body · 5 amino acids each. Met-enkephalin C27H35N5O7S, molecular weight 573.7 (PubChem CID 443363); Leu-enkephalin C28H37N5O7, 555.6 (CID 461776)
The enkephalins are two pentapeptides, Met-enkephalin (YGGFM) and Leu-enkephalin (YGGFL), identified in 1975 as the brain's own ligands for opiate receptors. They are cut from precursor proteins and act at opioid receptors. What they are, how they were found, the human evidence and why none is an approved drug.
Last checked 2026-10-26
Enobosarm (ostarine, GTx-024, MK-2866)
Not a peptide — a small molecule · Not a peptide: a non-steroidal small molecule, C19H14F3N3O3, molecular weight 389.3 (PubChem CID 11326715)
Enobosarm, sold online as ostarine or MK-2866, is a small non-steroidal molecule that acts on the androgen receptor. It is not a peptide. Two phase 3 trials of about 650 patients in lung cancer did not meet their physical-function goal, it has never been approved anywhere, and its developer is now testing it beside semaglutide.
Last checked 2026-09-23
Epitalon
Not approved anywhere · 4 amino acids
Epitalon is a four-amino-acid peptide from pineal extract, claimed to lengthen telomeres. The claims are real published findings — the question is who published them.
Last checked 2026-09-07
Eptifibatide (formerly Integrilin; now generic eptifibatide injection)
FDA-approved (since 1998) · A cyclic heptapeptide: 6 amino acids plus 1 mercaptopropionyl residue, closed by a disulfide bridge; molecular weight 831.96 (label)
Eptifibatide is a ring-shaped peptide of six amino acids plus one capping residue that stops platelets clumping. It was designed by copying barbourin, a protein from the venom of the southeastern pigmy rattlesnake, and is given as a drip in hospital during heart attacks and stenting. The original brand, Integrilin, is discontinued; generics remain.
Last checked 2026-10-05
Erythropoietin (EPO; epoetin as a medicine)
Made by the body · 166 amino acids once its 27-residue signal sequence is removed, with three N-linked and one O-linked sugar chain and two disulfide bonds — about four times the 40-residue line US regulation uses for proteins (UniProt P01588; 21 CFR 600.3)
Erythropoietin is a 166-amino-acid glycoprotein hormone, made mainly in the kidney, that tells the bone marrow how many red blood cells to make. What it is, the four approved US versions and their boxed warning, what the blood test measures, and the short peptide built from it.
Last checked 2026-10-27
Exenatide (Byetta, Bydureon, Bydureon BCise, generic exenatide injection — all discontinued)
FDA-approved (since 2005) · 39 amino acids, C-terminal amide; molecular weight 4,186.6 (Byetta label)
Exenatide is a 39-amino-acid peptide first identified in the venom of the Gila monster. Approved in 2005 as Byetta, it opened the GLP-1 drug class. Every exenatide product in the US, branded and generic, is now listed as discontinued (Drugs@FDA, 2026-10-14).
Last checked 2026-10-14
F
Follistatin
Not approved anywhere · 288 or 315 amino acids, depending on the form
Follistatin blocks myostatin, the brake on muscle growth. That biology is real and well established — but the only trial giving it to people delivers a gene, not a peptide. What it is and what is known.
Last checked 2026-09-08
G
Ganirelix acetate (Organon's ganirelix acetate injection; generics including Fyremadel)
FDA-approved (since 1999) · 10 amino acids (a decapeptide); molecular weight 1,570.4 as the anhydrous free base (label)
Ganirelix is a ten-amino-acid copy of the brain hormone GnRH, rebuilt at six positions so that it blocks the hormone's receptor instead of stimulating it. In IVF it stops the body's own LH surge from releasing eggs before they can be collected. Approved in the US in 1999, it now has six generic versions.
Last checked 2026-10-02
Gastrin (main circulating forms gastrin-17 and gastrin-34, 'big gastrin')
Made by the body · Several lengths cut from one 101-residue precursor: gastrin-71, -52, -34, -17, -14 and -6. Gastrin-17 and gastrin-34 are the two major bioactive forms (UniProt P01350)
Gastrin is a peptide hormone made in the lower stomach that tells the stomach lining to secrete acid. It circulates mainly as gastrin-17 and gastrin-34, shares its receptor and its last five amino acids with cholecystokinin, and is measured in blood when a gastrin-making tumour is suspected. Acid-suppressing drugs raise it. No gastrin medicine is approved.
Last checked 2026-10-06
GHK-Cu (Copper Tripeptide-1)
Never approved as a medicine · 3 amino acids
GHK-Cu is a three-amino-acid fragment of human collagen that carries a copper ion. Exactly one randomized controlled trial is indexed for it, in 13 patients, and it found no objective benefit. What the compound is, and what is and is not established.
Last checked 2026-09-07
Ghrelin (acyl-ghrelin; ghrelin-28, with a minor ghrelin-27 form)
Made by the body · 28 amino acids (ghrelin-27 lacks the last one), with an octanoyl group on serine 3
Ghrelin is a 28-amino-acid hormone first purified from the stomach. It signals hunger and triggers growth-hormone release through the receptor that ipamorelin, GHRP-2, GHRP-6 and MK-677 were designed to hit. It is active only when an eight-carbon fatty acid is fixed to its third amino acid.
Last checked 2026-09-30
GHRP-2 (pralmorelin, GPA-748, KP-102)
Peptide · 6 amino acids
GHRP-2 is a six-amino-acid growth hormone secretagogue with 43 randomized controlled trials behind it and one regulatory approval in the world. The approval is for a diagnostic test, and the reason it works as a test is the reason it is weak as a treatment.
Last checked 2026-09-13
GHRP-6 (growth hormone-releasing peptide-6)
Peptide · 6 amino acids
GHRP-6 has a real human pharmacology literature — including a published pharmacokinetic study in nine volunteers. It also has zero entries in the trial registry, and the reason is a date rather than a verdict.
Last checked 2026-09-11
GIP (glucose-dependent insulinotropic polypeptide; gastric inhibitory polypeptide)
The body's own hormone · 42 amino acids — two over the 40-residue line US regulation uses for proteins (UniProt P09681; 21 CFR 600.3)
GIP is a 42-amino-acid gut hormone that boosts insulin release when blood sugar is high — one of the two incretins, alongside GLP-1. It is the backbone tirzepatide and retatrutide are built on. Its sequence, its two names, why it loses much of its effect in type 2 diabetes, and where it stands.
Last checked 2026-10-17
Glatiramer acetate (Copaxone, Glatopa)
FDA-approved (since 1996) · Not a single length: a mixture of polypeptides with an average molecular weight of 5,000–9,000 daltons (label) — roughly 47–84 residues at the mixture's average residue mass of about 107 daltons (our arithmetic)
Glatiramer acetate, sold as Copaxone and as generics, is not one peptide but a mixture of synthetic polypeptides built at random from four amino acids — glutamic acid, alanine, tyrosine and lysine. It is approved for relapsing forms of multiple sclerosis. Its make-up, its five placebo-controlled trials and the anaphylaxis warning on its label.
Last checked 2026-10-15
GLOW (GHK-Cu + BPC-157 + TB-500)
Not a compound — a three-peptide mixture · Not applicable. GLOW is a mixture of three separate molecules of 3, 15 and 7 residues, not a single chain.
GLOW is a three-peptide mixture — GHK-Cu, BPC-157 and TB-500. Between them the three have eight registered studies, four of which administer the compound to a person, and none of the eight has posted a result.
Last checked 2026-09-19
GLP-1 (glucagon-like peptide-1; active forms GLP-1(7-36) amide and GLP-1(7-37))
Made by the body · The active forms are 30 amino acids (GLP-1(7-36) amide) and 31 (GLP-1(7-37)); the full-length GLP-1(1-37) is 37 and is not insulin-releasing (UniProt P01275; Mojsov 1987)
GLP-1 is the body's own 30- or 31-amino-acid hormone, cut from the proglucagon precursor in gut L-cells after a meal. It raises insulin, lowers glucagon and slows the stomach — and is broken down by the enzyme DPP-4 almost as soon as it is released. The hormone, its discovery and why the medicines are different molecules.
Last checked 2026-10-20
GLP-2 (glucagon-like peptide-2)
Made by the body · 33 amino acids, no disulfide bonds
GLP-2 (glucagon-like peptide-2) is a 33-amino-acid hormone cut from the same precursor as glucagon and GLP-1. Released by the gut after a meal, it thickens the lining of the small intestine and improves absorption. It was shown to do that in 1996. Its one approved copy, teduglutide, treats short bowel syndrome; it is not a weight-loss drug.
Last checked 2026-10-03
GLP-3 (glucagon-like peptide 3)
Does not exist in humans · No human molecule. The chondrichthyan peptide is a third proglucagon-derived product alongside GLP-1 and GLP-2.
Humans make GLP-1 and GLP-2 and stop. A glucagon-like peptide 3 does exist, in cartilaginous fish, and the one study of what it does found it did not move glucose. What searchers are usually reaching for is retatrutide.
Last checked 2026-09-16
Glucagon (Baqsimi, Gvoke, generic kits); analogue: dasiglucagon (Zegalogue)
FDA-approved · 29 amino acids — a single chain identical to human glucagon
Glucagon is the pancreas's 29-amino-acid counterweight to insulin: it tells the liver to release stored sugar. As a drug it treats severe low blood sugar and relaxes the gut for X-rays. Since 2019 it has come as a nasal powder and a ready-to-inject liquid, and a modified version, dasiglucagon, is approved separately. It only works if the liver has sugar to release.
Last checked 2026-09-24
Glutathione
Naturally occurring tripeptide · 3 amino acids
Glutathione has more published research than anything else in this library — 207,068 papers — and 57 entries in the US drug label database. We read all 57. They are homeopathic remedies and skin-whitening creams.
Last checked 2026-09-10
Gonadorelin
Formerly FDA-approved · Decapeptide (10 amino acids)
Gonadorelin is synthetic GnRH, the hormone that tells the pituitary to release LH and FSH. It had two US approvals, both discontinued. What it is, what it does, and what the evidence covers.
Last checked 2026-09-08
Goserelin acetate (Zoladex 3.6 mg and 10.8 mg implants)
FDA-approved (since 1989) · 10 amino acids (a decapeptide); molecular weight 1,269 as the free base (Zoladex label)
Goserelin is a ten-amino-acid copy of the brain hormone GnRH, changed at two positions so that it lasts. Given as a small biodegradable implant every 28 days or 12 weeks, it first stimulates and then shuts down the sex hormones. Zoladex has been US-approved since 1989 for prostate and breast cancer, endometriosis and endometrial thinning.
Last checked 2026-10-02
Growth hormone-releasing hormone (GHRH; also GRF or GHRF, somatoliberin, somatocrinin)
Made by the body · 44 amino acids ending in leucine amide (UniProt P01286, residues 32–75 of a 108-residue precursor). That is just over the 40-residue line US regulation uses for proteins (21 CFR 600.3); a 40-residue form was also isolated in 1982.
Growth hormone-releasing hormone is a 44-amino-acid hormone from the hypothalamus that tells the pituitary to release growth hormone. It was first sequenced in 1982 from pancreatic tumours that had caused acromegaly, and two approved drugs — sermorelin and tesamorelin — are built on it.
Last checked 2026-11-02
H
hCG (human chorionic gonadotropin)
FDA-approved, prescription only · Two chains: an alpha subunit of 92 amino acids and a beta subunit of 145 — 237 in total, plus attached sugars
Human chorionic gonadotropin is a two-chain placental hormone, FDA-approved for fertility and a few hormone conditions. Every US label opens by saying it is not effective for obesity. What it is, what it does, and what the evidence shows.
Last checked 2026-09-17
Hepcidin (hepcidin-25; also described as LEAP-1, liver-expressed antimicrobial peptide)
Made by the body · 25 amino acids (hepcidin-25), with 8 cysteines paired into 4 disulfide bonds; a shorter hepcidin-20 also circulates
Hepcidin is a 25-amino-acid hormone made by the liver that controls how much iron enters the blood. It works by making cells destroy ferroportin, the only known channel iron leaves them through. In August 2026 the FDA approved rusfertide (Mimrylo), a hepcidin mimetic, for the excess red-cell production of polycythemia vera.
Last checked 2026-09-30
Hexarelin
Not approved anywhere · Hexapeptide (6 amino acids)
Hexarelin is a growth hormone secretagogue with a substantial human literature from the 1990s and no ClinicalTrials.gov record at all. What it is, why the registry is empty, and what the evidence covers.
Last checked 2026-09-08
Humanin (HN)
Peptide · 24 amino acids
Humanin is a peptide your own mitochondria make, with 542 published papers and 312 carrying a human tag. Every one of its seven trial-registry records measures it rather than gives it — including the two filed as interventional.
Last checked 2026-09-13
I
IGF-1 LR3
Not approved anywhere · 83 amino acids
IGF-1 LR3 is a modified insulin-like growth factor made to be long-acting in cell culture. It was designed as a lab reagent, and that origin explains most of the confusion.
Last checked 2026-09-07
Incretins (the incretin hormones: GIP and GLP-1)
Made by the body · GIP 42 amino acids (UniProt P09681); GLP-1 30 or 31 in its active forms, GLP-1(7-36) amide and GLP-1(7-37) (UniProt P01275)
Incretins are gut hormones released after eating that make the pancreas release more insulin than the same blood sugar would on its own. There are two: GIP (42 amino acids) and GLP-1 (30–31). How the incretin effect was measured, why it shrinks in type 2 diabetes, why both hormones vanish within minutes, and how that led to the incretin drugs.
Last checked 2026-10-26
Insulin-like growth factor 1 (IGF-1; somatomedin C) — approved as mecasermin (Increlex)
Made by the body · 70 amino acids in a single chain, held by three internal disulfide bridges; molecular weight 7,649 Da (Increlex label)
IGF-1 (insulin-like growth factor 1) is a 70-amino-acid protein hormone that the body makes in response to growth hormone, and a link in the chain through which growth hormone drives growth. Its approved copy, mecasermin (Increlex), treats a rare group of children who make too little of it — and its commonest side effect in trials was low blood sugar.
Last checked 2026-10-05
Ipamorelin
Never approved · 5 amino acids
Ipamorelin's entire registered human development was two Phase 2 trials for postoperative ileus, both finished by 2013, neither followed by anything. What it is, what the trials found, and why almost nobody selling it mentions them.
Last checked 2026-09-07
K
Kisspeptin
Not approved · Kisspeptin-10 is 10 amino acids
Kisspeptin is the upstream signal that starts the reproductive hormone cascade. Real human research exists — and kisspeptin-10 is on the FDA's current compounding restriction list.
Last checked 2026-09-07
KLOW (GHK-Cu + BPC-157 + TB-500 + KPV)
Not a compound — a four-peptide mixture · Not applicable. KLOW is a mixture of four separate molecules of 3, 7, 15 and 3 residues, not a single chain.
KLOW is not a compound. It is a four-peptide mixture — GHK-Cu 50 mg, BPC-157 10 mg, TB-500 10 mg, KPV 10 mg — and the component it is least sold for makes up 72% of the molecules in the vial.
Last checked 2026-09-18
KPV
Not approved anywhere · 3 amino acids
KPV is the last three amino acids of alpha-MSH, studied for anti-inflammatory effects. What the fragment does, and why the evidence stops where it does.
Last checked 2026-09-07
L
L-carnosine (beta-alanyl-L-histidine); related: anserine (beta-alanyl-3-methyl-L-histidine)
Made by the body · 2 amino acids: beta-alanine + L-histidine; C9H14N4O3, molecular weight 226.23 (PubChem CID 439224)
Carnosine is a dipeptide — beta-alanine joined to histidine — that the body keeps in muscle and brain. It is sold as a supplement, not a drug. In a 2006 study, carnosine eaten in chicken broth did not appear in blood at all, yet four weeks of supplements raised muscle carnosine; the human trials of carnosine itself are small and mixed.
Last checked 2026-10-05
Lactoferrin (lactotransferrin, LTF) and lactoferricin, its N-terminal peptide
A milk protein, not a peptide · Human lactoferrin: 691 amino acids after a 19-residue signal sequence (UniProt P02788). Cow's-milk (bovine) lactoferrin: 689 (UniProt P24627). Bovine lactoferricin, the peptide released by pepsin: 25 amino acids
Lactoferrin is an iron-binding glycoprotein of about 690 amino acids found in breast milk, colostrum and mucosal secretions — a protein, not a peptide. When stomach pepsin cuts it, it releases lactoferricin, a short antimicrobial peptide. What both are, what lactoferrin is sold for, and what the large infant trials found.
Last checked 2026-10-20
Lanreotide acetate (Somatuline Depot; lanreotide injection from Cipla and, since September 2026, Amneal)
FDA-approved (since 2007) · 8 amino acids, closed into a ring by a disulfide bond between the two cysteines
Lanreotide is a ring-shaped peptide of eight amino acids that copies the hormone somatostatin. It treats acromegaly, slows the growth of certain neuroendocrine tumours and reduces carcinoid-syndrome rescue treatment. It needs no polymer to last a month: the peptide itself settles into a gel under the skin and seeps out with a half-life of 23 to 30 days.
Last checked 2026-09-30
Larazotide (larazotide acetate, AT-1001, INN-202)
Peptide · 8 amino acids
Larazotide is an eight-amino-acid peptide taken by mouth to tighten the gut barrier. Its 307-patient phase 3 in coeliac disease was terminated by its sponsor — and its code name, AT-1001, belongs to a completely different approved medicine.
Last checked 2026-11-03
Leptin (the product of the LEP gene, once called the obese or ob gene)
Made by the body · 146 amino acids once its 21-residue signal sequence is removed, with one disulfide bond — large enough that it is usually classed as a protein rather than a peptide
Leptin is a 146-amino-acid hormone made by fat cells that tells the brain how much energy the body has stored. It was cloned in 1994; its absence causes severe obesity from infancy. Its one approved drug form, metreleptin, treats generalised lipodystrophy — not ordinary obesity.
Last checked 2026-10-04
Leuprolide acetate (Lupron Depot, Lupron Depot-Ped, Eligard, Fensolvi, Camcevi; generic daily injection)
FDA-approved · 9 amino acids (a nonapeptide) — one shorter than the natural 10-amino-acid GnRH
Leuprolide (Lupron Depot, Eligard, Fensolvi, Camcevi) is a nine-amino-acid copy of the brain hormone GnRH. Given continuously, it first raises and then shuts down testosterone and oestrogen. It treats advanced prostate cancer, endometriosis, fibroids and early puberty. What it is, how the paradox works, and what its labels say.
Last checked 2026-09-27
Linaclotide (Linzess)
FDA-approved (2012) · 14 amino acids with three disulfide bridges; molecular weight 1,526.8 (Linzess label)
Linaclotide (Linzess) is a 14-amino-acid peptide held together by three disulfide bridges. Taken by mouth, it acts on the lining of the gut and is not measurable in the blood at label doses. Approved in 2012 for constipation-predominant IBS and chronic constipation, it carries a boxed warning against use in children under 2.
Last checked 2026-09-28
Lipo-C (lipotropic injection; MIC, methionine–inositol–choline)
Not a peptide — contains no amino acid chain · Not applicable. Lipo-C contains no peptide chain. Methionine is a single amino acid, which cannot form a peptide bond with itself; inositol is a sugar alcohol and choline is a nutrient, and neither is an amino acid at all.
Lipo-C contains no peptide. It is methionine, inositol and choline — one amino acid, one sugar alcohol and one nutrient — and the three-ingredient combination returns three PubMed records, two of them 1987 papers about mouse nerve.
Last checked 2026-09-19
Liraglutide (Victoza, Saxenda; also in Xultophy with insulin degludec)
FDA-approved (since 2010) · 31 amino acids — the same length as the natural hormone GLP-1(7-37)
Liraglutide is a 31-amino-acid copy of the gut hormone GLP-1 with one swapped amino acid and a fatty-acid tail that stretches its half-life from about two minutes to 13 hours. It is sold as Victoza for type 2 diabetes and Saxenda for weight management, carries a boxed warning based on rodent thyroid tumours, and has had US generic versions since 2024.
Last checked 2026-09-24
LL-37 (human cathelicidin, hCAP-18)
Naturally occurring antimicrobial peptide · 37 amino acids
LL-37 is the only cathelicidin the human body makes. Its research is large, entirely academic, and mostly measures the peptide rather than giving it — which is why no product exists.
Last checked 2026-09-10
M
Matrixyl
Cosmetic ingredient · Pentapeptide (5 amino acids) with a palmitic acid tail
Matrixyl is a cosmetic ingredient brand covering palmitoyl pentapeptide-4 and later blends. What the peptide is, what the small literature shows, and why the name itself makes the evidence hard to trace.
Last checked 2026-09-09
Matrixyl 3000 (palmitoyl tripeptide-1 + palmitoyl tetrapeptide-7)
Cosmetic ingredient · Two molecules: a tripeptide (3 amino acids, Gly-His-Lys) and a tetrapeptide (4 amino acids, Gly-Gln-Pro-Arg), each with a 16-carbon palmitic acid tail
Matrixyl 3000 is a cosmetic ingredient sold under a trade name that covers two different molecules, palmitoyl tripeptide-1 and palmitoyl tetrapeptide-7. What each one is, how it differs from the original Matrixyl, and what the small human record — one skin-permeation study in three people — actually shows.
Last checked 2026-10-27
Mazdutide
Not approved in the US · A peptide analogue of oxyntomodulin (development codes IBI362, LY3305677)
Mazdutide is a GLP-1 and glucagon dual agonist in late-stage development. Unlike almost everything else in this library, its 41 trial registrations come from fifteen different sponsors — not one.
Last checked 2026-09-09
Mechano growth factor (MGF; IGF-1Ec in humans, IGF-1Eb in rodents) and the synthetic MGF / PEG-MGF peptide
Made by the body · The sold peptide: 24 amino acids (the C-terminal end of the E peptide). The natural precursor: 158 residues in UniProt's isoform P05019-4.
Mechano growth factor is a form of IGF-1 that muscle makes after stretch or damage. The 'MGF' sold as a research peptide is its 24-amino-acid tail; the human studies measure the body's own MGF, and none gives the peptide to people.
Last checked 2026-10-28
Melanotan I (afamelanotide)
Peptide · 13 amino acids
Melanotan I is afamelanotide, and it is one of the few compounds in this library with a real approved product — a 16 mg implant for a rare genetic photosensitivity disease. Its US label lists the darkening of moles as a risk to be monitored twice a year.
Last checked 2026-09-15
Melanotan II
Unlicensed · Cyclic peptide
Melanotan II is an unlicensed melanocortin peptide sold for tanning. What it does, why its mechanism causes the side effects it does, and the documented harms.
Last checked 2026-09-07
Melittin (honeybee melittin, MLT)
Not approved as a medicine · 26 amino acids, C-terminal amide; cut from a 70-residue precursor (UniProt P01501)
Melittin is the main peptide of honeybee venom, about 40–60% of its dry weight. It punches holes in cell membranes, which is why it hurts, why it destroys red blood cells, and why its cancer and antiviral promise has stayed in the laboratory.
Last checked 2026-10-28
Micafungin (as micafungin sodium; brand Mycamine, now generic)
FDA-approved (since 2005) · A cyclic hexapeptide — six amino acids closed into a ring — carrying a fatty side chain (ChEBI, via PubChem CID 477468); micafungin sodium is C56H70N9NaO23S, molecular weight 1,292.26 (label)
Micafungin is an antifungal medicine whose core is a ring of six amino acids — a cyclic lipopeptide of the echinocandin class. It blocks the making of a sugar polymer the fungal cell wall needs and human cells do not have. It is approved by intravenous infusion for Candida bloodstream and oesophageal infections and for prevention in stem-cell transplant patients.
Last checked 2026-10-06
MK-677 (ibutamoren)
Not approved anywhere in the records checked · Not a peptide: a spiro-indoline-piperidine small molecule, C27H36N4O5S, 528.7 Da (PubChem CID 178024); trials used the mesylate salt
MK-677, or ibutamoren, is not a peptide: it is a small molecule of 528.7 Da that Merck developed in the 1990s to copy ghrelin's action on the growth-hormone secretagogue receptor, taken by mouth. It was never approved. What it is, what its trials in older adults and hip-fracture patients found, and why one was stopped early.
Last checked 2026-10-22
MOTS-c
Never approved · 16 amino acids
MOTS-c is a 16-amino-acid peptide encoded inside mitochondrial DNA. Humans have it measured constantly in research; almost nobody has been given it. Why that distinction is the whole story.
Last checked 2026-09-07
N
N-acetyl semax amidate (NA-Semax-Amidate; N-acetyl semax)
Research-market variant · 7 amino acids, the same as semax, plus an acetyl cap at the front and an amide cap at the end
N-acetyl semax amidate is semax with two chemical caps added, one at each end. It is a different molecule from semax, registered in PubChem only in December 2024, and every source that deposited it there is a chemical supplier. PubMed has no paper that uses the name. The one cell study of the acetylated form found it lost a protective effect semax has.
Last checked 2026-09-23
NAD+ (nicotinamide adenine dinucleotide)
Not a peptide — a dinucleotide coenzyme · Not applicable. It contains no amino acids and no peptide bonds.
NAD+ is a dinucleotide coenzyme with no amino acids and no peptide bonds. It reaches this library because clinics sell it beside peptide injections — and its 264 registered trials mostly do not give NAD at all.
Last checked 2026-09-18
Natriuretic peptides (ANP, BNP, CNP, urodilatin)
Made by the body · ANP 28 amino acids; BNP 32; CNP 22 (CNP-22) or 53 (CNP-53); urodilatin 32 — all cut from longer precursors (UniProt P01160, P16860, P23582)
Natriuretic peptides are a family of ring-shaped hormones — ANP (28 amino acids), BNP (32), CNP (22 or 53) and urodilatin (32) — that make the kidneys shed salt and water and relax blood vessels. Two infused copies failed large heart-failure trials; what reached patients was a blood test, a neprilysin blocker and a CNP drug for children's growth.
Last checked 2026-11-03
Neotame
Approved food additive (US, 2002) · Two amino acids — aspartic acid and phenylalanine — as a methyl ester, with a 3,3-dimethylbutyl group on the aspartic acid's nitrogen; C20H30N2O5, molecular weight 378.5 (PubChem CID 9810996)
Neotame is a high-intensity sweetener made by attaching a dimethylbutyl group to aspartame, itself a dipeptide of aspartic acid and phenylalanine. FDA approved it in 2002 for foods generally (except meat and poultry), put its sweetness at 7,000–13,000 times sugar and set an acceptable daily intake of 18 mg per person.
Last checked 2026-11-03
Noopept (omberacetam, GVS-111)
Modified dipeptide — the smallest compound in this library · 2 amino acids, both ends chemically modified
Noopept is the smallest compound in this library — a modified dipeptide designed from piracetam's structure in Moscow. Its mechanism story rests on a metabolite found in rats, and the one human pharmacokinetic study found no metabolites at all.
Last checked 2026-09-15
O
Octreotide acetate (Sandostatin, Sandostatin LAR Depot, Mycapssa, Bynfezia Pen)
FDA-approved (since 1988) · 8 amino acids, closed into a ring by a disulfide bond between positions 2 and 7
Octreotide is a ring-shaped peptide of eight amino acids that copies the hormone somatostatin, which switches off growth hormone and many gut hormones. It treats acromegaly and the diarrhoea and flushing of certain hormone-secreting tumours. It is injected, given as a long-acting depot, or — since 2020 — swallowed as a capsule that needs about 200 times the injected dose to reach the same exposure.
Last checked 2026-09-24
Orexin-A and orexin-B (hypocretin-1 and hypocretin-2)
Made by the body · Orexin-A: 33 amino acids, two disulfide bonds, a capped start (pyroglutamate) and an amidated end. Orexin-B: 28 amino acids, a straight chain with an amidated end
Orexin-A (33 amino acids) and orexin-B (28) are two neuropeptides made by a small cluster of nerve cells in the hypothalamus. They hold the brain awake. Found by two groups in 1998, they are missing in narcolepsy with cataplexy. The approved drugs that act on them — suvorexant, lemborexant, daridorexant — block their receptors and are not peptides.
Last checked 2026-10-03
Orforglipron (LY3502970)
Not a peptide — a small molecule · Not applicable. It has no amino acids and no peptide bonds.
Orforglipron switches on the GLP-1 receptor from a completely different chemistry — an 883-dalton small molecule, taken as a daily tablet. 53 registered studies, 27 of them phase 3, 33,058 participants.
Last checked 2026-09-16
Osteocalcin (bone Gla protein, BGP; the product of the BGLAP gene)
Made by the body · 49 amino acids in the mature chain (UniProt P02818, residues 52–100 of a 100-residue precursor). That is over the 40-residue line US regulation uses for proteins (21 CFR 600.3), although the literature often calls it a peptide.
Osteocalcin is a 49-amino-acid protein made by bone-building cells, the most abundant non-collagen protein in bone and a blood marker of bone formation. Mouse work since 2007 proposed it also acts as a hormone on blood sugar and fertility; a 2020 knockout strain found neither effect.
Last checked 2026-11-02
Oxytocin
FDA-approved as an injection · Nonapeptide (9 amino acids)
Oxytocin is a nine-amino-acid hormone, approved in the US as an injection to start or strengthen labour and control bleeding after birth. It is sold as a 'love hormone' nasal spray. What it is, what it does, and what the trials show.
Last checked 2026-09-17
P
P21 (P021, Ac-DGGL(A)G-NH2)
Ambiguous name — two unrelated things · Five units: four residues of CNTF (positions 148–151, D-G-G-L) plus one adamantylated glycine added at the end; written Ac-DGGL(A)G-NH2 or Ac-DGGLAG-NH2, with blocking groups at both ends; molecular weight 578.3 Da as published
P21, or P021, is a small CNTF-derived compound studied for memory in mice. Searching the name mostly returns p21 the cell-cycle protein, which has tens of thousands of papers to this compound's seventeen. What each one is, and why the confusion matters.
Last checked 2026-09-20
Palopegteriparatide (Yorvipath)
FDA-approved (since 2024) · 34-amino-acid peptide, PTH(1-34), carried on a branched 40 kDa (2 × 20 kDa) methoxypolyethylene glycol; whole molecule about 47.4 kDa (label)
Palopegteriparatide, sold as Yorvipath, is the 34-amino-acid front end of parathyroid hormone attached to a 40 kDa polyethylene glycol carrier through a linker that releases it slowly. It is approved for adults with hypoparathyroidism. Its chemistry, its one placebo-controlled trial and the label's warnings.
Last checked 2026-10-22
Parathyroid hormone (PTH, parathormone)
The body's own hormone · 84 amino acids — over the 40-residue line, so a protein by US regulation (UniProt P01270; 21 CFR 600.3)
Parathyroid hormone (PTH) is an 84-amino-acid hormone from four small glands in the neck that keeps blood calcium in a narrow range, acting on bone and kidney. Its sequence, its receptor, the PTH blood test, and the drugs made from it — full-length Natpara and the 34-residue front end used in teriparatide and Yorvipath.
Last checked 2026-10-17
Parathyroid hormone-related protein (PTHrP, PTH-rP; the product of the PTHLH gene)
Made by the body · Three forms from one gene: 139, 141 or 173 amino acids after a 36-residue signal and pro sequence is removed (UniProt P12272 isoforms 2, 1 and 3; Suva et al. 1987 reported the 141-residue form). All are well over the 40-residue line US regulation uses for proteins (21 CFR 600.3).
Parathyroid hormone-related protein is a 139-to-173-amino-acid protein, found in 1987 as the factor some cancers release to raise blood calcium. It shares its opening stretch with parathyroid hormone, works through the same receptor, and is the model for the osteoporosis drug abaloparatide.
Last checked 2026-10-27
Pegcetacoplan (Empaveli, Syfovre)
FDA-approved (Empaveli 2021, Syfovre 2023) · Two identical pentadecapeptides (15 positions each) on the two ends of a linear 40 kDa PEG; about 43.5 kDa in all, C1970H3848N50O947S4 (label)
Pegcetacoplan is two identical 15-residue peptides joined to the ends of a 40 kDa polyethylene glycol chain. It blocks complement protein C3 and is sold under two names: Empaveli, injected under the skin for PNH and two kidney diseases, and Syfovre, injected into the eye for geographic atrophy. Its structure, its trials, its warnings.
Last checked 2026-10-22
Pegvisomant (Somavert)
Approved drug (US, 2003) · 191 amino acids — the length of human growth hormone, with nine substitutions — plus several 5-kDa polyethylene glycol (PEG) chains, giving molecular weights of about 42, 47 and 52 kDa (Somavert label, section 11). Far over the 40-residue protein line in 21 CFR 600.3.
Pegvisomant is a 191-amino-acid, PEG-coated variant of human growth hormone that blocks the growth hormone receptor instead of activating it. Approved in 2003 as Somavert for acromegaly, it normalised IGF-1 in 89% of patients on the highest dose in its 12-week trial.
Last checked 2026-11-02
Pentadeca Arginate (PDA, also written pentadecapeptide arginate)
One patent (US 9,850,282, priority 2013) · 15 residues, if the product is what the name says. The 2013 patent on BPC-157 salts describes the fifteen-residue BPC-157 chain paired with arginine; no public chemical database holds a structure record under the market name, so whether a given product matches the patent's compound is not checkable from the record.
PDA is marketed as an improved BPC-157. Its one public record is a 2013 patent on BPC-157's arginine salt; re-searched on 2026-10-07 it still has no PubChem record, no PubMed paper and no registered study.
Last checked 2026-10-07
Peptide YY (PYY; the active short form is PYY3-36)
Made by the body · 36 amino acids, ending in a tyrosine amide (UniProt P10082, residues 29–64 of a 97-residue precursor). The circulating short form PYY3-36 is 34 amino acids. Both are under the 40-residue protein line.
Peptide YY is a 36-amino-acid hormone released by the gut after eating. Its shortened form, PYY3-36, cut food intake by about a third when infused into volunteers in 2002 and 2003 — but no PYY medicine has been approved.
Last checked 2026-11-02
Peptidoglycan (murein)
Made by bacteria, not by people · Not a fixed length: one continuous mesh per bacterial cell, built from glycan (sugar) strands joined by short peptides of a few amino acids
Peptidoglycan is the mesh that forms the cell wall of most bacteria: long sugar strands cross-linked by short peptides into one closed bag around the cell. It is not a peptide product and nobody takes it. It matters to medicine because penicillin-type antibiotics block its construction and the body's lysozyme breaks it down.
Last checked 2026-10-05
Phalloidin (a phallotoxin, from Amanita phalloides)
Natural toxin · A small cyclic peptide: molecular formula C35H48N8O11S, molecular weight 788.9 (PubChem CID 441542). ChEBI classes it as a homodetic cyclic peptide; its second ring is a tryptathionine bridge, the cross-link typical of the bicyclic Amanita peptides.
Phalloidin is a bicyclic peptide from the death-cap mushroom that locks actin filaments in place. Its toxicity is why it was studied; its grip on actin is why, since 1979, fluorescent phalloidin has been one of the standard ways to stain the cell skeleton under the microscope. It is not a medicine.
Last checked 2026-11-02
Pinealon (Glu-Asp-Arg, EDR)
Not approved anywhere we could confirm · 3 amino acids; C15H26N6O8, molecular weight 418.40 (PubChem CID 10273502)
Pinealon is the synthetic tripeptide Glu-Asp-Arg (EDR), one of the short 'bioregulator' peptides developed at the St Petersburg Institute of Bioregulation and Gerontology. It is sold online for memory and brain ageing. The record behind it: 22 PubMed records, mostly cell and rat studies, two small human reports, no randomised trial and no registered study.
Last checked 2026-10-15
Polymyxin B (polymyxin B sulfate; also in combination eye and ear products such as Maxitrol)
FDA-approved (since the 1960s) · A cyclic peptide with a long fatty-acid tail (ChEBI); the main component, polymyxin B1, is C56H98N16O13, mass 1,203.5, with a 6-methyloctanoyl group at its amino end (ChEBI:8309)
Polymyxin B is a cyclic peptide antibiotic with a fatty tail, made by the soil bacterium Bacillus polymyxa. It attacks the outer membrane of Gram-negative bacteria. Most of its US products are eye and ear drops that combine it with other antibiotics; the injection carries a boxed warning for kidney and nerve toxicity and is now used as a last resort against resistant infections.
Last checked 2026-10-14
Pramlintide acetate (Symlin, SymlinPen)
FDA-approved (2005) · 37 amino acids; molecular weight 3,949.4 (Symlin label)
Pramlintide (Symlin) is a 37-amino-acid copy of the hormone amylin with three amino acids swapped for proline. Approved in 2005 as a mealtime add-on to insulin, it carries a boxed warning for severe low blood sugar. Every Symlin presentation is now listed as discontinued in the US, with no generic. It is the ancestor of today's amylin weight-loss candidates.
Last checked 2026-09-27
Procalcitonin (PCT)
Made in the body · 116 amino acids (residues 26–141 of the 141-residue CALCA product, after the 25-residue signal peptide is removed; UniProt P01258)
Procalcitonin is the 116-amino-acid precursor of the hormone calcitonin, made from the CALCA gene. In bacterial infection and sepsis its blood level rises, and FDA-cleared assays use it as one input to antibiotic decisions. What the molecule is, what the cleared tests say a value is associated with, and what it cannot tell on its own.
Last checked 2026-10-14
Prolactin (PRL; the product of the PRL gene)
Made by the body · 199 amino acids once its 28-residue signal sequence is removed, held by three disulfide bonds — about five times the 40-residue line US regulation uses for proteins (UniProt P01236; 21 CFR 600.3)
Prolactin is a 199-amino-acid hormone of the anterior pituitary, best known for driving milk production. It is held in check mainly by dopamine from the brain, and its blood test can mislead when much of it circulates as 'macroprolactin'. What it is, what raises it, and what is and is not established.
Last checked 2026-10-20
PT-141 (Bremelanotide)
FDA approved · Peptide, melanocortin receptor agonist
PT-141 is bremelanotide, approved in the US in 2019 as Vyleesi for one specific use in premenopausal women. What the label covers, its stated limitations, and its documented warnings.
Last checked 2026-09-06
R
Relaxin (relaxin-2, the main human form)
Made by the body · 53 amino acids in two chains — an A chain of 24 and a B chain of 29 — joined by two disulfide bonds, with a third inside the A chain
Relaxin is a hormone of two short peptide chains, 24 and 29 amino acids long, held together by disulfide bonds. Best known for loosening ligaments and softening the cervix in pregnancy, it was developed as a heart-failure drug, serelaxin, which missed its endpoints in a 6,545-patient trial in 2019. No relaxin medicine is approved.
Last checked 2026-10-03
Retatrutide
Not approved anywhere · Peptide, GIP backbone
Retatrutide activates three hormone receptors and produced the largest weight losses yet reported in a phase 2 obesity trial. It is also not approved in any country, and every registered trial of it belongs to one company.
Last checked 2026-09-22
Romiplostim (Nplate)
FDA-approved (since 2008) · Two identical chains, each an IgG1 Fc fragment joined at its C-terminus to a peptide carrying two thrombopoietin-receptor-binding domains (label) — protein-sized overall
Romiplostim, sold as Nplate, is a peptibody: two copies of a short engineered peptide that switches on the thrombopoietin receptor, each fused to an antibody fragment that keeps it in the blood. It is approved for immune thrombocytopenia and for radiation injury to the bone marrow. Its design, its label trials and its warnings.
Last checked 2026-10-15
S
Secretin (synthetic human secretin: ChiRhoStim)
Made by the body · 27 amino acids, cut from a 121-residue precursor (UniProt P09683, residues 28–54); synthetic human secretin is C130H220N44O39, molecular weight 3,039.44 (ChiRhoStim label)
Secretin is a 27-amino-acid peptide hormone made in the duodenum that tells the pancreas to release bicarbonate-rich juice and neutralise stomach acid. Bayliss and Starling described it in 1902. A synthetic human copy is approved for pancreatic and gastrinoma testing; trials of secretin for autism found no benefit.
Last checked 2026-10-11
Selank
Not approved in the US or EU · Heptapeptide
Selank is a synthetic peptide based on tuftsin, developed in Russia as an anti-anxiety drug. What it is, where it is used, and how thin the independent evidence is.
Last checked 2026-09-07
Selank amidate (Selank amide; TKPRPGP-NH2 as the name implies)
Research-market name · 7 amino acids, the same as Selank, with the end carboxylic acid replaced by an amide, if the name is taken literally
Selank amidate is sold as a capped version of Selank, the Russian anti-anxiety peptide, with an amide in place of the free acid at its end. PubChem has no record under the name, and PubMed has no paper that uses it. Every published Selank study tested the plain peptide. What the name would mean chemically, and what is not known.
Last checked 2026-10-02
Semaglutide
Approved medicine · 31 amino acids
Semaglutide is the GLP-1 drug behind Ozempic, Wegovy and Rybelsus. What it is, what each product is approved for, and why a milligram number on a semaglutide package means nothing until you know which product it belongs to.
Last checked 2026-09-23
Semax
Registered in Russia · 7 amino acids
Semax is prescribed in Russia and has been studied there since the 1990s. It has 207 PubMed records, a single indexed randomized trial, and zero interventional studies on ClinicalTrials.gov. What that combination means.
Last checked 2026-09-07
Sermorelin
Was approved (US) · 29 amino acids
Sermorelin was a licensed American medicine sold as GEREF. It was discontinued in the 2000s, and FDA recorded that the withdrawal was not for safety or effectiveness reasons. What it is, what it was approved to do, and what that history does and does not mean.
Last checked 2026-09-07
Setmelanotide acetate (Imcivree)
FDA-approved (2020) · 8 amino acids, cyclic; molecular mass 1,117.3 daltons (Imcivree label)
Setmelanotide (Imcivree) is an eight-amino-acid ring-shaped peptide that switches on the brain's MC4 receptor. Approved in 2020, it treats obesity caused by rare genetic defects, Bardet-Biedl syndrome and, since a later label, acquired hypothalamic obesity. It is not a general weight-loss drug, and two in three patients in one trial saw their skin darken.
Last checked 2026-09-28
SLU-PP-332
Not a peptide · Not applicable — a small synthetic molecule, not a chain of amino acids
SLU-PP-332 is sold as an exercise in a bottle. Its entire published record is ten papers, all preclinical — and two of the ten exist only so anti-doping laboratories can detect it.
Last checked 2026-09-11
SNAP-8 (acetyl octapeptide-3)
Peptide · 8 amino acids
SNAP-8 is an eight-amino-acid cosmetic peptide sold as a topical wrinkle treatment. Its entire clinical record is two microneedle-patch studies — and in both of them it is one ingredient among several, compared against a patch containing nothing.
Last checked 2026-09-13
Somatostatin (somatotropin release-inhibiting factor; SST-14 and SST-28)
Made by the body · 14 amino acids (somatostatin-14) or 28 (somatostatin-28, the same 14 with 14 more at the front)
Somatostatin is a 14-amino-acid hormone, with a longer 28-amino-acid form, that switches off growth hormone and a long list of gut and pancreatic hormones. It was isolated from sheep brain tissue in 1973. It has no US drug approval of its own; octreotide, lanreotide and the oral octreotide capsule are the ring-shaped copies that were built to outlast it.
Last checked 2026-09-30
Somatropin (recombinant human growth hormone, HGH, rhGH; the hormone itself is somatotropin, product of the GH1 gene)
Made by the body · 191 amino acids, about 22,000 daltons, with two disulfide bonds — nearly five times the 40-residue line US regulation uses for proteins (UniProt P01241; Norditropin label; 21 CFR 600.3)
Somatropin is recombinant human growth hormone: a 191-amino-acid protein with the same sequence as the hormone the pituitary makes. It is approved for children with growth failure and adults with growth hormone deficiency, and US law restricts its distribution to approved uses. Its structure, the pituitary-extract era it replaced, the long-acting versions and where it stands.
Last checked 2026-10-20
SS-31 (Elamipretide)
Approved in the US for Barth syndrome (2025) · Tetrapeptide
SS-31 is elamipretide, approved in the US in September 2025 as FORZINITY for Barth syndrome. What its trials found, including where they missed.
Last checked 2026-10-03
Substance P
Made by the body · 11 amino acids, with an amidated methionine at the end
Substance P is an 11-amino-acid neuropeptide released by sensory nerves. It signals pain, widens blood vessels and drives inflammation through the NK1 receptor. Found in 1931 and sequenced in 1971, it has never been an approved medicine itself; the approved drugs, such as aprepitant for chemotherapy nausea, block its receptor.
Last checked 2026-10-03
Survodutide
Not approved anywhere · A peptide analogue of glucagon (development code BI 456906)
Survodutide activates the GLP-1 and glucagon receptors. Its 26 registrations are all but one from Boehringer Ingelheim, and a large part of the programme targets liver disease rather than weight.
Last checked 2026-09-09
T
TB-500
Not approved anywhere · 7 amino acids
TB-500 is Ac-LKKTETQ, a seven-amino-acid fragment of the 43-amino-acid protein thymosin beta-4. Why the two are constantly conflated, what that changes, and what the evidence covers.
Last checked 2026-09-06
Teduglutide (Gattex)
FDA-approved (2012) · 33 amino acids; molecular weight 3,752 daltons (Gattex label)
Teduglutide (Gattex) is a 33-amino-acid copy of the gut hormone GLP-2 with a single swap — glycine for alanine at position 2 — that shields it from the enzyme DPP-4. Approved in 2012 for short bowel syndrome, it helps the remaining intestine absorb more, cutting intravenous feeding. Its label requires colonoscopy because it can speed the growth of polyps.
Last checked 2026-09-28
Teriparatide (Forteo; Bonsity; generics) — PTH(1-34)
FDA-approved (since 2002) · 34 amino acids — the first 34 of the 84-amino-acid human parathyroid hormone
Teriparatide is the working front end of parathyroid hormone — its first 34 amino acids out of 84 — made by bacteria and injected once a day to treat osteoporosis at high fracture risk. In its main trial it cut new spine fractures from 14.3% to 5.0%. It is gone from the blood within three hours, and that brief daily pulse is what builds bone.
Last checked 2026-09-24
Terlipressin acetate (Terlivaz)
FDA-approved (2022) · 12 amino acids; molecular weight 1,227.38 as the free base (Terlivaz label)
Terlipressin is a 12-amino-acid peptide: lysine vasopressin with three glycines added to the front. The body trims them off, so it acts both as itself and as a slow source of vasopressin. In 2022 it became the first US-approved drug to improve kidney function in hepatorenal syndrome, with a boxed warning for serious or fatal respiratory failure.
Last checked 2026-10-02
Tesamorelin
FDA approved · 44 amino acids
Tesamorelin is FDA-approved as EGRIFTA for reducing excess abdominal fat in HIV patients with lipodystrophy. What the label says, what it explicitly does not cover, and why that distinction matters.
Last checked 2026-09-06
Tesofensine
Not a peptide · Small molecule
Tesofensine is a small-molecule triple monoamine reuptake inhibitor, not a peptide. Where it came from, the weight-loss results, and why it is sold in peptide catalogues at all.
Last checked 2026-09-07
Testagen (Lys-Glu-Asp-Gly, KEDG)
Not approved anywhere · 4 amino acids
Testagen is the tetrapeptide Lys-Glu-Asp-Gly from the St Petersburg bioregulator programme. Its name points to the testes; its indexed papers study thyroid and thymus tissue in hypophysectomised birds, and none is a human trial.
Last checked 2026-10-28
Thymalin (thymus polypeptide complex)
Not a single peptide — a mixture · Not a single defined length — a complex of polypeptides isolated from thymus tissue
Thymalin is not a single peptide but a polypeptide complex extracted from thymus tissue. It has been used clinically in Russia for decades and has 195 human-tagged papers — and zero entries in the international trial registry.
Last checked 2026-09-11
Thymogen (oglufanide; L-glutamyl-L-tryptophan; IM862)
Used in Russia as an immunomodulator · 2 amino acids — a dipeptide
Thymogen is the dipeptide glutamyl-tryptophan, a synthetic immunomodulator described in Russian journals since at least 1992. Searched by its own name, the international trial registry is empty. Searched by its American code, IM862, it went through a 202-patient phase 3 in Kaposi's sarcoma — and did no better than placebo.
Last checked 2026-09-23
Thymosin (a family name, first used in 1966 for factors from calf thymus)
A name, not a single compound · Depends on which thymosin: thymosin alpha-1 28 amino acids (UniProt P06454); thymosin beta-4 43 (UniProt P62328); TB-500 7; thymosin fraction 5, the original extract, 'at least 40 mostly small acidic polypeptides' of 1,000–15,000 Da (Goldstein 2007)
'Thymosin' is not one molecule. The name was given in 1966 to factors extracted from calf thymus, and it now covers peptides that share almost nothing but history: thymosin alpha-1 (28 amino acids, a licensed medicine outside the US), thymosin beta-4 (43, found in most cells), TB-500 (a seven-residue fragment) and the Russian thymus preparations. Which is which, and where each entry is.
Last checked 2026-10-26
Thymosin Alpha-1
Not FDA-approved · 28 amino acids
Thymosin alpha-1 is an immune-signalling peptide with 64 randomized controlled trials behind it and no FDA approval. What it is, what it is used for, and why its evidence sits outside the US record.
Last checked 2026-09-08
Thymosin beta-4 (Tβ4, TMSB4X)
43-amino-acid protein — the parent molecule of TB-500 · 43 amino acids
Thymosin beta-4 is a 43-amino-acid protein with a genuine registered clinical programme — 18 trials, three of them phase 3. None of them studies the injury it is sold to heal.
Last checked 2026-09-16
Thyrotropin-releasing hormone (TRH, protirelin)
Made by the body · 3 amino acids; C16H22N6O4, molecular weight 362.38 (PubChem CID 638678)
Thyrotropin-releasing hormone (TRH) is a tripeptide — pyroglutamyl-histidyl-prolinamide — made in the hypothalamus. It tells the pituitary to release TSH, which in turn drives the thyroid. Its structure, how one precursor carries six copies of it, its Nobel history and why its US diagnostic products are discontinued.
Last checked 2026-10-15
Tirzepatide
Approved medicine · 39 amino acids
Tirzepatide is the GIP and GLP-1 agonist sold as Mounjaro and Zepbound. What it is, how it differs from a single-receptor drug, and what its labels state — including the one indication almost nobody knows it holds.
Last checked 2026-10-07
Trevogrumab (REGN1033, SAR391786)
Not a peptide — a monoclonal antibody · Not applicable in the peptide sense: a full-size human IgG antibody
Trevogrumab is a monoclonal antibody, not a peptide, that blocks myostatin. Searched by name, the trial registry shows one study; searched by its code REGN1033, it shows eight, back to 2012. What it is, what it does, and what has and has not been reported.
Last checked 2026-09-17
Triptorelin
FDA-approved · Decapeptide (10 amino acids)
Triptorelin is a ten-amino-acid GnRH agonist with two current US approvals — advanced prostate cancer and precocious puberty in children. Both use it to suppress sex hormones. What it is, how it works, and what the labels show.
Last checked 2026-09-17
V
Vancomycin (as vancomycin hydrochloride; brand Vancocin, many generics)
FDA-approved · A heptapeptide core — seven amino acids — cross-linked into three rings and carrying two sugars; vancomycin hydrochloride is C66H75Cl2N9O24·HCl, molecular weight 1,485.71 (injection label)
Vancomycin is a glycopeptide antibiotic: a core of seven amino acids, cross-linked into three rings and carrying sugars, made by a soil bacterium. It blocks the building of the bacterial cell wall. Given into a vein it treats serious staphylococcal infections, including MRSA; swallowed, it stays in the gut and treats C. difficile diarrhoea.
Last checked 2026-10-11
Vasopressin (arginine vasopressin, AVP; antidiuretic hormone, ADH; Vasostrict)
FDA-approved (Vasostrict, 2014) · 9 amino acids, with a disulfide ring between positions 1 and 6
Vasopressin is the pituitary's nine-amino-acid antidiuretic hormone. At higher levels it also tightens blood vessels, and as a drug that is its whole job: an intravenous infusion for adults in shock whose blood pressure stays low despite fluids and other medicines. Its first FDA approval, Vasostrict, dates only from 2014, and that label rests on published studies rather than a pivotal trial.
Last checked 2026-09-24
VIP (vasoactive intestinal peptide)
Naturally occurring hormone · 28 amino acids
VIP is one of the most-studied peptides in human physiology — and the only record in the US drug label database is a raw powder listed by a chemical supplier. What it is, and why the gap is so wide.
Last checked 2026-09-09
Vipivotide tetraxetan (PSMA-617, in Pluvicto)
FDA-approved (since 2022, as Pluvicto) · Not a chain of standard peptide bonds: glutamate and lysine joined by a urea, plus 2-naphthylalanine and a cyclohexane linker (our reading of the label's chemical name); C49H68(177Lu)N9O16, 1,216 g/mol (label)
Vipivotide tetraxetan (PSMA-617) is the targeting half of Pluvicto, a radioactive prostate-cancer drug. It is a peptidomimetic — built from amino-acid pieces joined partly by a urea bond — rather than a classic peptide. How it works, its three label trials and its warnings.
Last checked 2026-10-17
Vosoritide (Voxzogo)
FDA-approved (since 2021, accelerated approval) · 39 amino acids; C176H290N56O51S3, molecular weight 4.1 kDa (label) — one residue under the 40-residue protein line
Vosoritide, sold as Voxzogo, is a 39-amino-acid analogue of C-type natriuretic peptide (CNP), lengthened by two residues so an enzyme cannot cut it. It is approved under accelerated approval to increase growth in children with achondroplasia. Its sequence, its one placebo-controlled trial and what that trial did not measure.
Last checked 2026-10-15
W
Wolverine stack (BPC-157 + TB-500)
Not a compound — a two-peptide mixture · Not applicable. It is a mixture of a 15-residue peptide and a 7-residue one.
A 1:1 blend of BPC-157 and TB-500. Neither is what its name suggests, and the registered human evidence for both halves traces to eight filings by one sponsor, none of them updated since the day it was posted.
Last checked 2026-09-18
Z
Ziconotide acetate (Prialt)
FDA-approved (2004) · 25 amino acids with three disulfide bridges; molecular weight 2,639 daltons (Prialt label)
Ziconotide (Prialt) is a 25-amino-acid peptide copied from the venom of the fish-hunting cone snail Conus magus. It blocks N-type calcium channels on pain nerves in the spinal cord. Approved in 2004, it is given only by continuous infusion into the spinal fluid, and it carries a boxed warning for severe psychiatric and neurological effects.
Last checked 2026-09-28
By question, rather than by compound
Amino Acid Chart: The Twenty, With the Masses Derived Rather Than Copied
A reference table of the twenty standard amino acids with codes, formulas and residue masses — every number computed from the formula, and the method checked against a real peptide's published mass.
Are Peptides Good for You, or Safe? The Library Counted
Peptides are a chemical class, not a product. Of this library's 107 compound entries, 30 are approved medicines; the research-market best sellers have almost no human record.
Myostatin Inhibitor Peptides: Every Drug in Trials Is an Antibody or a Fusion Protein, Not a Peptide
Myostatin is the body's brake on muscle growth, and blocking it is one of the most tested ideas in muscle medicine. The candidates with human results are antibodies and a receptor-fusion protein. The 'myostatin peptide' sold in vials, follistatin-344, has never been tested as an injected protein in a completed trial.
Peptide vs Protein: The Chemistry Draws No Line, US Law Draws One at 40, and Insulin Crossed It in 2020
A peptide and a protein are built the same way, from amino acids joined by peptide bonds. Where one becomes the other is a convention. US drug law is the one place with a hard number: over 40 amino acids is a protein, counting chains that belong together, which is why insulin became a biologic on 23 March 2020 and semaglutide did not.
Peptides for Energy: One Has an Approved Label, and Its Fatigue Trial Missed
Elamipretide, MOTS-c and humanin are the mitochondrial peptides sold for energy. One is now an approved medicine for an ultra-rare disease. Its phase 3 measuring fatigue and walking distance was terminated for missing both endpoints.
Peptides for Focus and Mood: The Russian Compounds and the Evidence Problem
Semax, Selank, Cerebrolysin and Dihexa. Most of the nootropic peptides come from one research tradition — and that shapes what the evidence can tell you.
Peptides for Healing: Every Registered Trial of the Compounds People Buy for It, Counted
BPC-157, TB-500, GHK-Cu, pentadeca arginate and thymosin beta-4 are the healing peptides. Their entire registered clinical record comes to twenty-six studies, none of them in a tendon or ligament, and two of them describe themselves as examples.
Peptides for Immunity: What Is Real Biology and What Is Marketing
Thymosin alpha-1, LL-37, KPV and the immune peptides. Which have genuine clinical use somewhere in the world, and why 'boosting immunity' is the wrong frame.
Peptides for Inflammation: The One With Sixty-Six Trials Is Not the One Being Sold
KPV, BPC-157, ARA-290 and thymosin alpha-1 are the peptides discussed for inflammation. KPV has no registered trial at all; thymosin alpha-1 has sixty-six and is barely marketed for this. What each record holds.
Peptides for Joints and Tendons: Where the Healing Claims Come From
BPC-157, TB-500 and the rest of the healing group. What the animal evidence shows, what the human evidence does not, and why this is the category with the widest gap.
Peptides for Longevity: The Claims, and What Sits Behind Them
Which peptides are sold on longevity claims, what the evidence for each looks like, and the problem with measuring an intervention meant to work over decades.
Peptides for Menopause: The Peptide That Matters Most Is the Body's Own, and the Approved Drugs Block It
Hot flushes run through a peptide signal in the brain, neurokinin B. Infusing it caused flushes in eight of ten women in a controlled study. The two FDA-approved non-hormonal treatments block its receptor, and neither is a peptide. The peptide sold for desire, bremelanotide, is labelled for premenopausal women only.
Peptides for Sleep: What Is Actually Being Studied, and What Is Not
Which peptides are discussed for sleep, what the evidence behind each one looks like, and why the strongest sleep effects in this field are side effects of something else.
The Peptide Bond: What It Is, and the Arithmetic You Can Check Yourself
A peptide bond joins two amino acids and loses one water molecule — 18.015 daltons. That single number lets anyone verify a peptide's published mass from its sequence, and spot a modification the letters do not show.
The Peptide Chain: What It Is, and How Long the Real Ones Are
A peptide chain runs from an N-terminus to a C-terminus and is numbered from the N end. Across this library's own entries the median chain is ten residues long — and a quarter of the compounds shelved as peptides have no chain at all.
What Are Peptides? A Plain Explanation, and What They Actually Do
A peptide is a short chain of amino acids. What that means, how peptides differ from proteins and from drugs, which ones are approved medicines, and how to read a claim about one.
What Peptides Are Used For: An Index of This Library, by Purpose
Every compound in this library grouped by what it is sold for — and a count of how many are approved by any regulator anywhere. Nine of sixty, and six of those nine are approved for something other than the use they are sold for.