Mechanism · Research Data · Side Effects · No Doses
AHK-Cu is a copper-binding tripeptide studied mainly in human hair-follicle and cell cultures. One published study reported follicle elongation and changes in dermal papilla cells, but that is not the same as proving hair growth in people. There are no published human randomised trials specific to AHK-Cu. Its evidence base is much thinner than GHK-Cu's, so conclusions should stay cautious.
AHK-Cu — L-alanyl-L-histidyl-L-lysine complexed with copper(II), also referenced in cosmetic-ingredient literature as Copper Tripeptide-3 — is a synthetic copper-binding tripeptide in the same broad family as GHK-Cu (Copper Tripeptide-1). The two are structurally related but distinct: GHK-Cu's sequence is glycyl-L-histidyl-L-lysine, while AHK-Cu substitutes alanine for glycine as the first residue. Both peptides chelate a copper(II) ion, but they have been studied through separate, and very differently sized, bodies of research.
AHK-Cu's research profile is narrow. The compound is discussed mainly in the context of a single study that examined AHK-Cu in human hair follicles ex vivo and cultured dermal papilla cells. The study did not test GHK-Cu. This guide is for educational and research purposes only. It is not medical advice or evidence of an approved treatment.
The following table summarises the current types of evidence available for AHK-Cu in scientific literature.
| Evidence Type | Status |
|---|---|
| Human Randomised Controlled Trials (RCTs) | ✗ (No published human RCTs identified for AHK-Cu specifically) |
| Ex Vivo Human Tissue Studies | ✔ (Human hair follicle organ culture — one identified study) |
| In Vitro Studies | ✔ (Human dermal papilla cell and dermal fibroblast culture) |
| Animal Studies | ✗ (No animal-model studies specific to AHK-Cu identified, unlike GHK-Cu) |
| Regulatory Approval for Human Therapeutic Use | ✗ (Not approved by HPRA, FDA, or EMA) |
Like GHK-Cu, AHK-Cu is studied as a copper-delivery tripeptide: it complexes a copper(II) ion and is investigated for its ability to influence cellular signalling in skin and hair follicle tissue. The identified research examined AHK-Cu's effects on dermal papilla cells (the signalling cells at the base of the hair follicle that regulate the hair growth cycle) and on dermal fibroblasts.
In that research, AHK-Cu at low (picomolar to nanomolar range) concentrations was reported to increase proliferation of both dermal papilla cells and dermal fibroblasts, to increase fibroblast production of vascular endothelial growth factor (VEGF) — a signalling protein linked to blood supply to the follicle — and to decrease fibroblast secretion of transforming growth factor-beta1 (TGF-β1), a protein associated with suppressing the hair growth (anagen) phase. The proposed mechanism is that supporting dermal papilla and fibroblast activity, while reducing a growth-suppressing signal, creates conditions more favourable to hair follicle growth — but this remains a proposed mechanism from a single body of tissue-culture research, not an established clinical mechanism.
The primary published research cultured human hair follicles ex vivo and reported that AHK-Cu, applied across a range of low concentrations, stimulated elongation of the follicles compared with untreated controls — used by the study's authors as a marker of a hair-growth-promoting effect in this tissue-culture model.
In cultured human dermal papilla cells, AHK-Cu was reported to increase cell proliferation. Because dermal papilla cells regulate whether a follicle stays in its growth phase, increased proliferation of these cells is the mechanistic link the study's authors drew to the observed follicle elongation.
The same body of research reported that AHK-Cu increased proliferation of human dermal fibroblasts, increased fibroblast VEGF output, and decreased fibroblast secretion of TGF-β1 — a combination the authors interpreted as supportive of a more growth-favourable follicle environment.
The identified study tested AHK-Cu, not GHK-Cu. The compounds are structurally related but distinct, so this result cannot substantiate a GHK-Cu hair-growth claim. The separate GHK-Cu Research Guide reviews its own evidence base.
| Study / Model | Reported Effect |
|---|---|
| Human Hair Follicle Organ Culture | AHK-Cu (10-12–10-9 M) stimulated elongation of cultured human hair follicles versus untreated control. |
| Human Dermal Papilla Cell Culture | Increased dermal papilla cell proliferation across the concentration range tested. |
| Human Dermal Fibroblast Culture | Increased fibroblast proliferation and VEGF production; decreased TGF-β1 secretion. |
The identified evidence is a single study examining AHK-Cu in ex vivo human hair-follicle organ culture and in vitro dermal papilla cells. It is not a clinical hair-loss trial. There is no dedicated trial pairing AHK-Cu with RU58841 or another compound, and findings should not be read across to GHK-Cu.
Because AHK-Cu's published research is limited to ex vivo and in vitro tissue-culture work, no human safety or tolerability data has been established through clinical trials. Copper-tripeptide complexes as a class — including the far better studied GHK-Cu — have generally been reported to cause localised irritation at the site of topical application in research settings, but this has not been specifically documented for AHK-Cu in human use.
Long-term human safety data for AHK-Cu has not been established through large-scale trials — this is a meaningful research gap, not a demonstrated safety profile. Researchers should treat the limited evidence base as a significant caveat.
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