AHK-Cu
AHK-Cu is a small peptide of three amino acids (alanine, histidine and lysine) bound to a copper ion. It is a close relative of GHK-Cu, with alanine in place of glycine. It is not approved as a medicine. Published research on it is very limited: the main study tested it on human hair follicles and cells in the lab, not in people.
Approval status
Not approved as a medicine anywhere. It does not appear on FDA’s lists of substances nominated for pharmacy compounding, so FDA has not reviewed its safety or quality.45
What it’s used or studied for
- Animal & lab only
Hair growth: in lab studies, it lengthened human hair follicles kept alive outside the body and helped hair-root (dermal papilla) cells grow.3
- No studies
Skin anti-aging effects and injected use are promoted online, but no published studies have tested either.
Each label shows how strong the evidence is: an approved use, human studies, animal or lab studies only, or a popular claim with no published studies. Being studied is not the same as being proven safe or effective.
Side effects
There are no published human safety data for AHK-Cu, applied to the skin or injected.3
Cautions
- No regulator has assessed AHK-Cu, so there is no official review of its safety or quality.4
Sources
- PubChem: AHK-Cu, copper complex of Ala-His-Lys, hydrochloride (CID 168431292)
- PubChem: L-Alanyl-L-histidyl-L-lysine (AHK) (CID 7408502)
- Pyo et al. (2007). The effect of tripeptide-copper complex on human hair growth in vitro. Arch Pharm Res
- FDA: Bulk drug substances nominated for compounding under section 503A, categories 1 to 3 (updated May 14, 2026)
- FDA: Bulk drug substances used in compounding that may present significant safety risks (current as of April 2026)
Spotted a mistake on this page? Report it. The email opens with the peptide and vial already filled in.