AHK-Cu: what the literature documents about this second copper tripeptide
Less well known than its cousin GHK-Cu, AHK-Cu is studied for its action on the hair follicle and the extracellular matrix: an overview of the research literature.
AHK-Cu (Ala-His-Lys, chelated to a Cu²⁺ ion) belongs to the same chemical family as GHK-Cu, but the literature devoted to it focuses on a different area: the hair follicle and the peri-follicular extracellular matrix.
A copper complex, a distinct field of study
Like GHK-Cu, AHK-Cu is a tripeptide capable of chelating copper — an essential cofactor of numerous enzymes involved in tissue remodeling. However, the in vitro research literature on AHK-Cu has historically focused on dermal papilla cells and keratinocytes, rather than on the general skin fibroblasts studied for GHK-Cu.
VEGF and peri-follicular angiogenesis
In vitro studies report a marked stimulation of VEGF (Vascular Endothelial Growth Factor) by dermal papilla cells exposed to AHK-Cu, supporting angiogenesis around the hair follicle. Good peri-follicular vascularization is a classic subject of study in hair cycle research, as it determines the supply of nutrients and oxygen to the matrix cells.
Modulation of the hair cycle and TGF-β2
Published work also describes a lengthening of the anagen phase (active growth phase) of the hair cycle in the studied models, associated with a modulation of TGF-β2 — a factor known in the literature for its inhibitory role on hair growth. The complex also stimulates the proliferation of keratinocytes and dermal fibroblasts.
Lysyl oxidase: a bridge to matrix remodeling
As with other copper-peptide complexes, the literature reports activation of lysyl oxidase, a copper-dependent enzyme essential for the cross-linking of collagen and elastin. This mechanism brings AHK-Cu close to GHK-Cu in terms of extracellular matrix remodeling, even though the two compounds are studied in different experimental contexts.
No systemic hormonal effect documented
Unlike peptides such as melanocortins or GH secretagogues, no systemic hormonal effect has been reported for AHK-Cu in the available in vitro models — a point that distinguishes this class of copper tripeptides from peptides with an endocrine receptor target.