GHK-Cu research spans more than 50 years, since Loren Pickart reported a growth-promoting factor in human blood in 1973, but almost all of it is in cells and animals.[1] In people, the record is thin: one positive trial in diabetic foot ulcers, one negative trial in leg ulcers, and a 2026 systematic review that found just 2 randomized trials among 20 studies of GHK-Cu in aesthetics.[8][7][12]

This page walks through the research history, separating what was shown in people from what was shown in the lab. For other repair-focused compounds, see our healing peptides hub.

Bottom line

AreaLab and animal evidenceHuman evidence
Collagen and tissue repairStrong and consistent[4][5]Indirect only
Diabetic foot ulcersSupportiveOne positive randomized trial (1994)[8]
Venous leg ulcersSupportiveOne negative randomized trial (1992)[7]
Skin aging and wrinklesStrong in cellsFew trials; the published one after laser treatment was mostly negative[9][11]
InjectionsLimitedNone published

A short history of GHK-Cu

1973: discovery. Pickart and Marvin Thaler reported a small factor in human serum that kept normal liver cells alive longer and stimulated growth in liver tumor cells.[1]

1977: identified. The factor was shown to be a tripeptide, glycyl-histidyl-lysine, or GHK.[2]

1980: the copper link. Pickart’s group proposed that GHK works by helping cells take up copper, an essential cofactor for enzymes that build connective tissue.[3]

1988: collagen. French researchers, working with Pickart, found that GHK-Cu stimulated collagen production by skin fibroblasts in culture, at extremely low concentrations.[4]

1990s: wound trials. The company ProCyte tested a GHK-Cu gel in chronic wounds, producing the two human ulcer trials described below.[7][8]

2000s to now: cosmetics and gene studies. GHK-Cu moved into skincare, and its discoverer published reviews arguing that it influences thousands of genes tied to repair and inflammation.[10]

Wound healing: the key studies

Rat wound chambers (1993). Steel mesh cylinders were implanted under the skin of rats and injected with GHK-Cu or saline. GHK-Cu produced a dose-dependent rise in collagen, protein and other repair-tissue components, while a control tripeptide did nothing.[5]

Ischemic wounds in rats (2003). In 24 rats with wounds made in skin with poor blood supply, a 2% GHK-Cu gel shrank wound area by 64.5% at day 13, versus 45.6% with vehicle gel and 28.2% with no treatment. Treated wounds also had lower levels of an inflammatory signal (TNF-alpha) and tissue-degrading enzymes.[6]

Venous leg ulcers (1992). In a randomized, evaluator-blinded trial with 86 evaluable patients, a 0.4% copper tripeptide cream did no better than an inert placebo. Silver sulfadiazine, a standard antibacterial cream, outperformed both.[7]

Diabetic foot ulcers (1994). In a multicenter, randomized, evaluator-blinded, placebo-controlled trial, all patients got intensive standard wound care. Adding GHK-Cu gel raised median closure of plantar ulcers to 98.5% versus 60.8% with vehicle, and infections were less common when treatment began right after debridement.[8] The trial was run with the manufacturer, and the gel was never approved as a drug.

Skin: the key studies

After laser resurfacing (2006). Thirteen patients who completed this randomized trial used skin care with or without GHK-Cu after CO2 laser treatment around the mouth. Blinded evaluators and computer analysis found no difference in redness, wrinkles or skin quality; only patients’ own questionnaire scores favored GHK-Cu.[9]

The widely quoted face-cream studies. Results often repeated online, such as improvements in dozens of women using copper peptide creams, come mainly from conference presentations and reports summarized in the discoverer’s reviews, not full peer-reviewed trials.[10]

Recent reviews. A 2025 review concluded that GHK-Cu clearly acts as an anti-wrinkle agent in cells but noted a “surprising absence of clinical studies.”[11] A 2026 systematic review of aesthetic uses included 20 studies, 18 of them preclinical and only 2 randomized trials.[12]

Established vs preliminary

Established:

  • GHK is a natural tripeptide in human blood that binds copper.[2][3]
  • GHK-Cu stimulates collagen and other repair molecules in cells and in rat wounds.[4][5]

Preliminary or uncertain:

  • Whether GHK-Cu meaningfully speeds human wound healing. The two ulcer trials point in opposite directions.[7][8]
  • Whether topical GHK-Cu visibly reduces wrinkles, and how well it penetrates skin.[11]
  • The broad gene-expression claims, which rest largely on computer analyses of existing data.[10]
  • Anything about injected GHK-Cu, which has no published human studies.

Limitations

  • Concentrated authorship. A large share of GHK-Cu papers and reviews come from its discoverer and associated groups, which limits independent confirmation.[10]
  • Industry funding. The 1990s wound trials were run with the company developing the gel.[8]
  • Cosmetic loophole. Skincare products don’t need clinical trials, so most GHK-Cu products have never been tested in published studies.
  • Delivery questions. GHK-Cu is water-loving and may not penetrate intact skin well, a problem researchers are trying to solve with microneedles.[13]

What’s next

  • Regulation: FDA placed injectable GHK-Cu on its list of compounding substances with possible safety risks in 2023, then removed it in April 2026 after the nomination was withdrawn. In May 2026, FDA said it was still evaluating GHK-Cu for non-injectable uses.[14][15]
  • Microneedle delivery: a 2026 review called for properly sized randomized trials of microneedle-delivered GHK-Cu, noting that none had yet been published.[13]

For a chronic wound, standard care from a wound specialist has far stronger evidence than any peptide product. Talk with a clinician before adding GHK-Cu to treatment.