What it is
Hepcidin is the liver's hormone for iron. Its active form, hepcidin-25, is a short, tightly folded peptide:
DTHFPICIFCCGCCHRSKCGMCCKT
Eight of its 25 amino acids are cysteines, and UniProt (P81172) records all eight paired into four disulfide bonds — a dense set of cross-links for a peptide this size. It is cut from an 84-residue precursor; a shorter hepcidin-20, missing the first five amino acids, also exists.
The human evidence here is of two kinds: physiology — how the hormone behaves in people — and, since August 2026, an approved drug that copies it. Hepcidin itself is not given as a treatment.
How it controls iron
UniProt's summary of the literature describes hepcidin as controlling the major flows of iron into the blood — from food, from recycled red cells and from stores:
- Iron leaves cells through one channel, ferroportin.
- Hepcidin binds ferroportin and makes the cell take it in and destroy it.
- With fewer channels, iron stays inside the cells that hold it — the gut cells that absorb it from food, the macrophages that recycle it from old red blood cells, and the liver cells that store it.
So more hepcidin means less iron reaching the blood, and less hepcidin means more. UniProt identifies it as the main circulating regulator of iron absorption and distribution.
First found as an antimicrobial
Hepcidin was described in 2000–2001 as an antimicrobial peptide in human blood and urine, which is why it also carries the name LEAP-1 (liver-expressed antimicrobial peptide). In laboratory tests UniProt records it as:
| Organism | Activity |
|---|---|
| E. coli, N. cinerea | Strong |
| S. epidermidis, S. aureus, group B streptococcus | Weaker |
| Candida albicans (fungus) | Active |
| Pseudomonas aeruginosa | None |
These are test-tube results. Its role in iron is what the later literature established as its main function.
The drug that copies it: rusfertide
On 2026-08-28 the FDA approved rusfertide (Mimrylo, Takeda; NDA 220605), which its label calls a hepcidin mimetic: a synthetic ring-shaped peptide, closed by a disulfide bond and carrying a palmitoyl fatty-acid chain, molecular weight 2,442.0. Like hepcidin, it blocks ferroportin. In polycythemia vera, a bone-marrow disease in which too many red cells are made, cutting the iron supply limits red-cell production.
The approving trial, VERIFY (NCT05210790), as reported on the label:
| Placebo (n = 146) | Rusfertide (n = 147) | |
|---|---|---|
| No phlebotomy eligibility, weeks 20–32 | 48 (32.9%) | 113 (76.9%) |
| Difference (95% CI) | — | 43.8% (33.5–54.2%) |
All patients had needed repeated phlebotomy (blood removal) before entering, and stayed on their existing treatment. The label's most common adverse reactions were injection-site reactions (56%) and anaemia (16%), and it warns of new or worsening high platelet counts. ClinicalTrials.gov lists six rusfertide studies (2026-09-30), including a completed 16-patient phase 2 in hereditary haemochromatosis, an inherited iron-overload disease.
Where it stands
Hepcidin is measured in research and in some specialist laboratories; it is not sold as a research peptide the way many entries in this library are. PubMed indexes 6,988 records for hepcidin, 242 tagged as randomised controlled trials, and 20 for rusfertide (2026-09-30). Iron test results belong with the clinician who ordered them.
Related reading
Like C-peptide, hepcidin is a body-made peptide whose everyday medical use is as a measurement rather than a product. For how its four disulfide bonds compare with the single bridge in most short peptides, see the peptide chain, and the amino acid chart for cysteine itself.