Peptide Briefs

GHK-Cu (Copper Peptide)

Evidence Grade: B — Human clinical data exists (wound-healing and cosmetic trials), but most trials are small, topical, and industry-adjacent.

What it is

GHK-Cu is the tripeptide glycyl-L-histidyl-L-lysine complexed with a copper(II) ion. GHK occurs naturally in human plasma, saliva, and urine; it was first isolated from human plasma by Loren Pickart in 1973. Plasma levels decline markedly with age.

Proposed mechanism

GHK binds copper with high affinity and appears to act as a signaling molecule rather than a structural one. In cell and gene-expression studies it has been associated with:

  • Upregulation of collagen, elastin, and glycosaminoglycan synthesis in fibroblasts
  • Modulation of matrix metalloproteinases and their inhibitors (tissue remodeling)
  • Chemoattraction of immune and repair cells to wound sites
  • Broad gene-expression shifts — one analysis reported GHK altering expression of roughly one-third of human genes in the dataset examined (a striking claim that has not been independently replicated at scale)

What the literature shows

Cell and animal: Consistent pro-collagen and wound-closure effects in fibroblast cultures and rodent wound models across several decades of work, most of it from the Pickart group.

Human: A 1994 randomized trial reported faster closure of diabetic foot ulcers with a topical GHK-Cu gel versus vehicle. Multiple small cosmetic trials (8–12 weeks, topical) report improved skin density, reduced fine lines, and better elasticity, generally measured by instrument rather than blinded clinical scoring. No controlled human trials of injected GHK-Cu were found.

Regulatory status

Not an approved drug in any jurisdiction. Widely used as a cosmetic ingredient. Not on the WADA Prohibited List as of the most recent list reviewed.

Gaps and caveats

  • Nearly all foundational work comes from a single research lineage; independent replication is thin
  • Topical cosmetic data does not transfer to other routes
  • The “one-third of genes” figure is from computational analysis of a gene-expression database, not a clinical outcome
  • Copper delivery in the complex is a real variable — GHK and GHK-Cu are not interchangeable in the literature

Key references