What the studies show
No human trial of any design. The single study kept plucked human follicles alive in a dish for a week and measured elongation.
Animal studies, cell studies, or anecdotes only. This is where almost every viral peptide sits. Promising and proven are different words for a reason.
- 1Pyo HK, Yoo HG, Won CH, et al. The effect of tripeptide-copper complex on human hair growth in vitro.Arch Pharm Res, 2007Ex vivo follicles and cultured dermal papilla cells; no human subjects.
- 2Searches of PubMed and trial registries for AHK-Cu in humans.LYO literature search, September 2026No clinical study identified.
In context
AHK-Cu is a copper-bound tripeptide — alanine, histidine, lysine — marketed for hair growth in serums and, increasingly, as an injectable alongside GHK-Cu. The entire evidence base is one 2007 laboratory study in which it lengthened human hair follicles kept alive in culture and made dermal papilla cells divide. No trial has applied it to a person's scalp, let alone injected it. It is a legal cosmetic ingredient and nothing more; GHK-Cu, by contrast, has small human trials for topical skin use.
AHK-Cu is cosmetic ingredient; no clinical evidence. Legal status differs by country — see the regulation section or the jurisdiction pages.
Questions
Is AHK-Cu proven to help with hair growth?
What studies are behind the grade?
Is AHK-Cu approved for this?
Other outcomes for AHK-Cu
- DHair follicle elongation (ex vivo)1 laboratory study
- DInjected use (skin, hair)None
- DSafety in humansadverseCosmetic-use experience only
Written and maintained by LYO Research — how pages are written and checked. Reviewed 10 September 2026. Grades count human evidence only; see how LYO grades. Not medical advice. Correct this page →