The first useful thing to say about KLOW is that it is not a compound. Every other kind of entry in this library describes one molecule: a sequence, a mass, a PubChem identifier. KLOW is a mixture of four separate peptides sold in a single vial, and almost everything confusing about it follows from that.
What is in the vial
The labels that publish a breakdown agree on the split. One research-supply label read on 2026-09-18 states it as "GHK-Cu 50 mg, BPC-157 10 mg, TB-500 10 mg, KPV 10 mg", with a "Total Peptide Content Per Vial" of 80 mg and a stated purity of "≥99% (HPLC), per component". Not every seller publishes the numbers — another product page checked the same day listed a 3 mL vial and the four names and no amounts at all.
| Component | What it is | Per vial |
|---|---|---|
| GHK-Cu | A copper-carrying tripeptide | 50 mg |
| BPC-157 | A 15-residue synthetic peptide | 10 mg |
| TB-500 | A 7-residue acetylated fragment | 10 mg |
| KPV | A 3-residue fragment of alpha-MSH | 10 mg |
| 80 mg |
That is a 5:1:1:1 ratio, and it is the same 50/10/10 backbone as the three-peptide blend sold as GLOW with 10 mg of KPV added. The letters do not otherwise decode: no published protocol, pharmacopoeia entry or regulatory filing defines either recipe. The composition is asserted by the people selling it.
Weighed, then counted
Milligrams are the wrong unit for comparing peptides to each other, because these four molecules differ in mass by a factor of four. A milligram of a small peptide is many more molecules than a milligram of a large one. Converting the label to micromoles — the stated milligrams divided by the published molecular weights — changes the picture substantially.
| Component | Molecular weight | Mass | By mass | Micromoles | By molecule count |
|---|---|---|---|---|---|
| GHK-Cu | 401.91 | 50 mg | 62.5% | 124.41 | 72.4% |
| KPV | 342.43 | 10 mg | 12.5% | 29.20 | 17.0% |
| TB-500 | 889.0 | 10 mg | 12.5% | 11.25 | 6.5% |
| BPC-157 | 1,419.5 | 10 mg | 12.5% | 7.04 | 4.1% |
| Total | 80 mg | 100% | 171.90 | 100% |
(Molecular weights from PubChem, read 2026-09-18. Micromoles = milligrams ÷ molecular weight × 1,000.)
BPC-157 is 4.1% of the molecules in the vial. It is also the name that brings most people to this blend. The two components KLOW is chiefly sold for — BPC-157 and TB-500, the tissue-repair pair — are together 25% of the mass and 10.6% of the molecules. Nearly three-quarters of what is in the vial is the copper tripeptide, which is the ingredient with the most cosmetic history and the least injectable one.
None of that says the formula is wrong. It says that a reader who pictures a repair blend with some skin support added has the proportions inverted.
What the registries hold, read one record at a time
On 2026-09-18, ClinicalTrials.gov held eight interventional studies naming any of the four components: four for BPC-157, three for GHK-Cu, one for TB-500, and none for KPV.
Eight is the number a search returns. It is not the number of studies in which someone was given one of these compounds. Reading all eight:
| Record | Component | What it actually does |
|---|---|---|
| NCT07803250 | BPC-157 | Phase 1, 30 participants, rotator-cuff repair. Administers it. Not yet recruiting. |
| NCT07437547 | BPC-157 | Phase 2, 120 participants, hamstring strain. Administers it. Recruiting. |
| NCT07752381 | BPC-157 | Completed, 40 participants — but the intervention is a commercial product, "Parlay Recover Peptide Gummies", not BPC-157 as a defined substance. |
| NCT02637284 | BPC-157 | Phase 1 in healthy volunteers, intervention listed as "Bepecin". Registry status UNKNOWN. |
| NCT07487363 | TB-500 | Phase 1/2, 80 participants, cardiovascular biomarkers. Administers it. Recruiting. |
| NCT07437586 | GHK-Cu | Phase 2, 60 participants. Administers it — as a topical gel on punch-biopsy wounds. |
| NCT07706361 | GHK-Cu | Gives an adhesive patch and measures blood GHK and GHK-Cu as the outcome. Does not give GHK-Cu. |
| NCT05932732 | GHK-Cu | A facial-treatment device study. GHK-Cu is not the intervention. |
So four of the eight administer the named compound to a person, and none of those four has posted a result. Two had not begun recruiting when checked, one is recruiting, and the fourth carries a status the registry uses when a record has gone unmaintained past its own completion date.
Two of the four that do not administer anything are the trap this library has documented repeatedly: a registry record can name a compound because the compound is being measured, not because it is being given. NCT07706361 is the clearest case — an adhesive patch is applied and GHK-Cu is what the blood is checked for.
The one thing given by the wrong route
The detail worth carrying away concerns the largest ingredient. GHK-Cu makes up 72.4% of the molecules in this vial, and the single registered study that gives it to people applies it as a gel to the skin.
A lyophilised vial is reconstituted and injected. The one piece of registered human evidence attached to the dominant component of the blend describes a topical gel on a standardised wound. That is not a criticism of the gel study, which is a placebo-controlled phase 2 design. It is a statement about what the evidence covers and what it does not.
Nothing has been tested as a mixture
No registered study names KLOW. A ClinicalTrials.gov search for any two of its components used together returned zero records on 2026-09-18.
This matters more for a blend than for a single compound. Combining four biologically active molecules raises questions that evidence about each one separately cannot answer — whether they interfere with each other, whether the proportions are the right ones, whether the mixture is stable in one vial. The premise of the formula is that the four do complementary jobs. That premise has not been tested; it has been assembled.
For the two-component version of the same question, see this library's entry on the Wolverine stack, where the registered human evidence for both halves turns out to trace to a single sponsor.
Where it stands
KLOW is not an approved product anywhere and is not a drug, a supplement or a cosmetic. It is sold under research-use-only terms — one label read for this entry states that it "is not a drug, food, cosmetic, or dietary supplement and has not been evaluated by the FDA". MuscleLedger covers the anti-doping status of the repair peptides in this blend.
Questions about whether any of this should be used, by anyone, for anything, belong with a clinician. This entry describes what is in the vial and what has been studied.
Related entries
- GHK-Cu — the copper tripeptide that is most of this vial
- BPC-157 — the 15-residue peptide the blend is best known for
- TB-500 — and why it is not the same molecule as thymosin beta-4
- KPV — the anti-inflammatory tripeptide, and the K in the name
- The Wolverine stack — the two-component repair blend