Summary

AHK-Cu (alanyl-histidyl-lysine-copper, also known as copper tripeptide-2) is a copper-binding tripeptide complex studied for its effects on hair follicle growth, skin repair, and wound healing. It has demonstrated stimulatory effects on dermal papilla cells and hair shaft elongation in vitro. Evidence is primarily preclinical, with no large-scale human clinical trials published.

Mechanism

AHK-Cu delivers copper ions to cells in a bioavailable tripeptide complex. In dermal papilla cells, AHK-Cu stimulates proliferation and upregulates VEGF (promoting vascularisation) while downregulating TGF-β1 (reducing catagen transition). The copper component serves as a cofactor for lysyl oxidase, an enzyme essential for collagen cross-linking and extracellular matrix stabilisation. This dual action — growth factor modulation and copper-dependent enzymatic support — underlies its proposed effects on hair growth and tissue repair.

Evidence base

Evidence Grading: Limited

All evidence is in vitro or preclinical. No human clinical trials have been published.

Key studies:

  • Pyo et al. (2007): AHK-Cu promoted hair shaft elongation in human hair follicle organ culture and stimulated dermal papilla cell proliferation, with upregulation of VEGF and downregulation of TGF-β1.
  • Pickart (2008): Reviewed the broader copper peptide literature, providing context for AHK-Cu's mechanism relative to GHK-Cu.
  • Sadgrove & Simmonds (2021): Reviewed safety of copper peptides in cosmetic applications.

Gap: No human clinical trial data for AHK-Cu specifically. Hair growth claims are based on in vitro organ culture only.

Protocols

Research-Only Protocols

No established human dosing protocols exist.

In published in vitro research:

  • Dermal papilla cell proliferation: AHK-Cu at 10⁻⁹ to 10⁻⁶ M
  • Hair follicle organ culture: Micromolar concentrations stimulated hair shaft elongation

No human topical or systemic dosing has been established in clinical trials.

AHK-Cu is not a licensed medicine in the UK and is not a controlled substance. Copper peptides are permitted in cosmetic formulations under UK cosmetics regulations. For research peptide supply, AHK-Cu falls into a grey area: it may be sold for bona fide research purposes but is not MHRA-approved for human therapeutic use. See our UK legal status guide for further detail.

Vendor notes

AHK-Cu may be available from UK research peptide suppliers and cosmetic ingredient suppliers. Request a Certificate of Analysis (COA) verifying purity and copper content. See the vendor vetting guide for evaluation criteria.

References

  1. Pyo HK, et al. "The effect of tripeptide-copper complex on human hair growth in vitro." Arch Pharm Res. 2007;30(7):834-839.
  2. Pickart L. "The human tri-peptide GHK and tissue remodeling." J Biomater Sci Polym Ed. 2008;19(8):969-988.
  3. Sadgrove NJ, Simmonds MSJ. "The topical and systemic safety of copper peptides in cosmetics." FASEB BioAdvances. 2021;3(11):847-855.