GHK-Cu
A naturally occurring human plasma tripeptide with copper affinity. Best evidence is in topical dermatology; systemic use has no controlled human trial support.
Skin & Cosmetic
AHK-Cu
A copper tripeptide marketed for hair growth, closely related to GHK-Cu. The published evidence is limited in-vitro work, mostly from cosmetic industry sources.
Overview
AHK-Cu is a close cousin of GHK-Cu, differing in one amino acid. Both carry copper, which is a required cofactor for the enzymes that build and cross-link collagen and elastin. The specific claim for AHK-Cu is hair follicle stimulation: in cell culture it has been reported to increase dermal papilla cell proliferation and prolong the growth phase of the hair cycle. There is no controlled human trial.
Ala-His-Lys complexed with copper(II) through the histidine imidazole and terminal amine. Copper is a cofactor for lysyl oxidase and superoxide dismutase, and copper peptides more generally influence matrix metalloproteinase and TIMP expression. Reported in-vitro effects include increased human dermal papilla cell proliferation, upregulation of VEGF and increased follicular keratinocyte activity, supporting anagen extension. Evidence is confined to cell culture and cosmetic formulation studies; no randomised controlled trial of hair or skin endpoints has been published.
Research areas
Hair growthDermal papilla biologyCopper peptide chemistry
Dosing reported in the literature
Every protocol below is reproduced from a published study or approved labelling, with its source named. These are records of what was studied — not recommendations, and not a suggestion that any of them is appropriate for any person.
| Protocol as reported | Source |
|---|---|
| Topical application in cosmetic serum formulations at sub-1% concentrationsNo clinical protocol exists — this describes commercial use, not a studied regimen. | Cosmetic ingredient literature |
Trial status
In-vitro and cosmetic formulation studies only. No randomised controlled trials.
Reported safety signals
- Topical copper peptides can cause contact irritation and, less commonly, sensitisation.
- No systemic human safety data exists; injection has no basis in any published study.
- Copper peptides are chemically incompatible with several common actives, notably direct-acid vitamin C, in the same routine.
Common questions
Is AHK-Cu better than GHK-Cu for hair?
No study has compared them in people. GHK-Cu has substantially more published research overall, most of it about skin. The hair-specific claims for AHK-Cu come from cell-culture work, which does not establish that it grows hair on a human head.
Primary sources
Medical disclaimer
This page is for informational and research purposes only. Nothing here constitutes medical advice. The compounds discussed are research chemicals. Consult a qualified clinician before starting any protocol.
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