A copper tripeptide close to GHK-Cu, sold for hair growth; the evidence is one study on human hair follicles kept alive in a dish.
Also called Alanyl-histidyl-lysine copper, L-alanyl-L-histidyl-L-lysine-Cu2+, Copper tripeptide (AHK)
AHK-Cu is alanine, histidine and lysine holding a copper ion. It differs from GHK-Cu by one amino acid (alanine instead of glycine), and the same Ala-His-Lys sequence sits at positions 2 to 4 of the copper-binding tip of human serum albumin. It shows up in scalp serums and in injectable research-chemical vials marketed for hair thickness.
The case for it comes down to one 2007 study from Seoul National University. Hair follicles taken from human scalps grew longer in culture when bathed in AHK-Cu at 1 picomolar to 1 nanomolar, and dermal papilla cells, the cells that drive the hair growth cycle, multiplied faster and showed fewer signs of programmed cell death. That is a lab result on tissue in a dish.
No one has published a controlled trial of AHK-Cu on a living person's scalp, topical or injected. It is not an approved drug, it is not on any FDA compounding list, and its safety when injected is unknown.
What it binds to, and what happens inside the body after that, step by step.
Like GHK, AHK binds copper and appears to act on fibroblast-type cells. In the one human tissue study, it made dermal papilla cells divide and shifted the balance of survival proteins (more Bcl-2 relative to Bax, less cleaved caspase-3), which the authors read as protection from programmed cell death. Earlier work on copper tripeptides showed fibroblasts making more VEGF, a blood-vessel growth signal, and less TGF-beta1.
Human results and animal results are kept apart below. A result in rats tells you a mechanism is plausible. It does not tell you what happens in a person.
The only direct evidence is one study on human scalp follicles and dermal papilla cells grown in a lab. No trial has tested AHK-Cu on people, so any claim about thicker hair or skin benefits in humans is an extrapolation from that dish work and from the better-studied GHK-Cu.
No human studies are among the key studies for AHK-Cu. Everything known comes from animals or cells.
Human scalp hair follicles (ex vivo) and cultured human dermal papilla cells
AHK-Cu at 1 picomolar to 1 nanomolar lengthened follicles and increased dermal papilla cell proliferation; the reduction in apoptotic cells at 1 nanomolar was not statistically significant.
Read the studyC3H mice
Copper peptide complexes from ProCyte stimulated hair follicles in mice; the short report does not identify AHK specifically.
Read the studyFuzzy rats and stump-tailed macaques
A copper-binding peptide (PC1031) enlarged hair follicles on rat back skin with an effect similar to topical minoxidil; the paper does not state that PC1031 is AHK.
Read the studyCell-free and cell assays
A synthetic analog of the albumin copper-binding tip (d-DAHK), which contains the AHK sequence, blocked copper-driven oxidant formation; this concerns DAHK, not AHK-Cu itself.
Read the studyThese are questions the published research has not answered.
No product containing AHK-Cu is approved as a medicine by the FDA.
Sold as a cosmetic ingredient in topical hair and skin products and as an unregulated research chemical for injection. No drug application has ever been filed. WADA does not name it. Injected research-grade product has no therapeutic approval anywhere, so it falls under S0 (non-approved substances), which is prohibited at all times. Topical cosmetic use is not a concern.
No human half-life has been published for AHK-Cu, so we do not draw a clearance curve. Half-lives quoted online for it are usually estimates from animal data.
No human study or approved label has published a dose for AHK-Cu, so there is no table to show.
No dose of AHK-Cu has been tested in a published human study or approved on a label. Numbers that circulate online come from animal studies scaled up by guesswork or from sellers. We do not reproduce them.
Which symptoms are expected and which mean stop and get help: side effects and red flags.
Tap a claim to see what the studies found.
The supporting study used human follicles kept alive in a dish. No trial on living scalps has been published.
No study has compared the two directly, in a dish or in people.
The AHK sequence is part of the albumin protein's copper-binding tip, but free AHK-Cu has not been shown to circulate in human blood the way GHK does.
There are no human data for either route, so speed and size of effect are unknown, and injection adds infection and impurity risk.
These pairings come up often. Almost none have been tested together in a trial, and the evidence note on each says so plainly.
No approved product or label guidance. Research suppliers usually list freezer storage away from light.
No published stability data for dissolved AHK-Cu.
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