GHK-Cu

CCosmetic ingredientcopper peptidecopper tripeptide-1glycyl-L-histidyl-L-lysine
In one paragraphGHK-Cu is a naturally occurring three-amino-acid peptide that binds copper, found in plasma, saliva and urine, with levels that fall with age. Applied to skin in creams it has modest evidence from small trials for improving fine lines and skin firmness, which is why it is a common cosmetic ingredient. Injected use — increasingly promoted online — has no human evidence of any kind.
Overall gradeC Weak
Human trialsSmall topical trials
Outcomes graded4
Last reviewed2 September 2026
EvidenceWhat it isHow it worksUnknownsRegulationQuestionsReferences

What the human research shows

A legitimate cosmetic ingredient with a small, mostly industry-funded human literature for topical use, and a grey-market injectable with none. The two uses share a name and nothing else on this page.

OutcomeGradeEffect sizeHuman studiesWhere the evidence comes from
Skin appearance (topical)CWeakSmall3–4 small trialsTwelve-week facial studies in the late 1990s and early 2000s reported improved skin laxity, clarity and fine lines versus vehicle or comparators. Small, short, largely industry-run.12
Wound healing (topical)CWeakSmallSmall trials, mixedA GHK-Cu gel was tested on diabetic foot ulcers in the 1990s with mixed results; the product was not carried forward.3
Hair growthDNo human evidenceNot measurableNone controlledClaims rest on cell and animal work and on analogy with minoxidil; no human trial.
Any outcome (injected)DNo human evidenceNot measurableNoneUnstudied in humans. Injecting a copper complex without data on distribution or dose is not a safety-neutral act.
AMultiple good human trials, consistentBSome human trials, mostly consistentCFew or weak human studiesDAnimal or anecdotal onlyeffect size · red = adverse

Literature searched to 2 September 2026. Human studies only; animal and cell work informs the mechanism section and nothing else.

What it is

GHK-Cu was isolated from human plasma in 1973 by Loren Pickart, who noticed that plasma from young people made old liver cells behave like young ones. The peptide's affinity for copper is what gives it biological activity, and much of what is written about it comes from Pickart's own laboratory over the following five decades.

It is used at low concentrations in serums and creams, and appears in the gene-expression literature as a molecule that shifts the activity of a large number of genes in cell culture — a finding that reads as more impressive than it is until it is tested in people.

How it is thought to work

Proposed mechanisms are plausible for skin: stimulation of collagen and elastin synthesis, recruitment of repair cells, and antioxidant effects, all shown in cultured cells and animal wounds. The topical trials are consistent with a modest effect on skin quality. Whether any of this happens after injection — and where the copper goes — is unknown.

What is still unknown

  • Whether topical benefits persist beyond the 12-week windows studied.
  • Anything at all about injected use: absorption, distribution, dose, safety.
  • How much of the cell-culture gene-expression data translates to living tissue.

Regulatory status

European Union
Permitted as a cosmetic ingredient

Listed in the EU cosmetic ingredient inventory. Injectable products are unlicensed medicines.

United States
Cosmetic ingredient; injectable unapproved

Legal in topical products. Not approved as a drug; injectable versions are sold as research chemicals.

United Kingdom
Cosmetic ingredient

As EU. Injectable use falls under unlicensed medicines rules.

Sport (WADA)
Not listed

Not a prohibited substance.

Questions people actually ask

Does GHK-Cu work for wrinkles?
Modestly, in small twelve-week studies of topical products — improvements in fine lines, firmness and skin clarity versus vehicle. The trials are small and mostly industry-funded, so the honest answer is “probably a little.”
Is injecting GHK-Cu safe?
Unknown. There are no human studies of injected GHK-Cu. Topical safety data does not transfer to injection.
Does GHK-Cu regrow hair?
No human trial has tested it. The claim comes from cell and animal studies and from its structural similarity to how minoxidil is thought to act.

References

  1. 1
    Pickart L, Margolina A. Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data.Int J Mol Sci, 2018;19:1987 (review)Review by the peptide's discoverer; declared interest.
  2. 2
    Leyden JJ, et al. Skin care benefits of copper peptide containing facial cream.American Academy of Dermatology meeting, 2002 (abstract)Twelve-week facial study; conference abstract, industry-supported.
  3. 3
    Mulder GD, et al. Enhanced healing of ulcers in patients with diabetes by topical treatment with glycyl-L-histidyl-L-lysine copper.Wound Repair Regen, 1994;2:259–269Small trial of a GHK-Cu gel on diabetic foot ulcers.

Change log

  • 2026-09-02Full page. Added wound-healing and hair rows, mechanism, regional status and FAQ.
  • 2026-09-01Initial publication.