GHK-Cu
Copper complex of glycyl-L-histidyl-L-lysine, widely studied in cell, skin and wound-healing models.
Mechanism & research rationale
GHK binds copper(II) and has been investigated for effects on extracellular-matrix turnover, collagen and glycosaminoglycan synthesis, metalloproteinase regulation, fibroblast activity, oxidative stress and wound-related signalling.
Human evidence
Some cosmetic and topical literature reports changes in skin appearance or matrix markers, but modern reviews highlight a surprising shortage of rigorous clinical studies and unanswered questions around skin permeability and formulation. Recent sports-medicine reviews find no convincing clinical evidence for injectable musculoskeletal use.
Preclinical / translational evidence
Cell and animal work is extensive relative to human trials and includes wound-healing, fibroblast, collagen, inflammatory and tissue-remodelling models. This supports biological plausibility but not broad clinical claims.
Key limitations
- Topical/cosmetic evidence should not be extrapolated to injectable research formats.
- Published formulations differ; copper complexation and delivery conditions can influence activity.
- Clinical efficacy and long-term safety for systemic use remain uncertain.