{"id":"ghk-cu","name":"GHK-Cu","aliases":["copper peptide","copper tripeptide-1","glycyl-L-histidyl-L-lysine"],"url":"https://lyoresearch.com/compounds/ghk-cu","summary":"GHK-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_grade":"C","overall_grade_meaning":"weak human evidence","human_trials":"Small topical trials","regulatory_status":"Cosmetic ingredient","outcomes":[{"outcome":"Skin appearance (topical)","grade":"C","grade_meaning":"weak human evidence","effect_size":"small","adverse":false,"human_studies":"3–4 small trials","evidence":"Twelve-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.","references":[{"citation":"Pickart L, Margolina A. Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data.","where":"Int J Mol Sci, 2018;19:1987 (review)","url":"https://pubmed.ncbi.nlm.nih.gov/?term=Pickart+Margolina+GHK-Cu+2018+review"},{"citation":"Leyden JJ, et al. Skin care benefits of copper peptide containing facial cream.","where":"American Academy of Dermatology meeting, 2002 (abstract)","url":"https://pubmed.ncbi.nlm.nih.gov/?term=copper+peptide+facial+cream+skin+laxity+12+week"}]},{"outcome":"Wound healing (topical)","grade":"C","grade_meaning":"weak human evidence","effect_size":"small","adverse":false,"human_studies":"Small trials, mixed","evidence":"A GHK-Cu gel was tested on diabetic foot ulcers in the 1990s with mixed results; the product was not carried forward.","references":[{"citation":"Mulder GD, et al. Enhanced healing of ulcers in patients with diabetes by topical treatment with glycyl-L-histidyl-L-lysine copper.","where":"Wound Repair Regen, 1994;2:259–269","url":"https://pubmed.ncbi.nlm.nih.gov/?term=Mulder+glycyl-histidyl-lysine+copper+diabetic+ulcers+1994"}]},{"outcome":"Hair growth","grade":"D","grade_meaning":"no human evidence","effect_size":"not measurable","adverse":false,"human_studies":"None controlled","evidence":"Claims rest on cell and animal work and on analogy with minoxidil; no human trial.","references":[]},{"outcome":"Any outcome (injected)","grade":"D","grade_meaning":"no human evidence","effect_size":"not measurable","adverse":false,"human_studies":"None","evidence":"Unstudied in humans. Injecting a copper complex without data on distribution or dose is not a safety-neutral act.","references":[]}],"regions":[{"region":"European Union","status":"Permitted as a cosmetic ingredient","note":"Listed in the EU cosmetic ingredient inventory. Injectable products are unlicensed medicines."},{"region":"United States","status":"Cosmetic ingredient; injectable unapproved","note":"Legal in topical products. Not approved as a drug; injectable versions are sold as research chemicals."},{"region":"United Kingdom","status":"Cosmetic ingredient","note":"As EU. Injectable use falls under unlicensed medicines rules."},{"region":"Sport (WADA)","status":"Not listed","note":"Not a prohibited substance."}],"faq":[{"q":"Does GHK-Cu work for wrinkles?","a":"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.”"},{"q":"Is injecting GHK-Cu safe?","a":"Unknown. There are no human studies of injected GHK-Cu. Topical safety data does not transfer to injection."},{"q":"Does GHK-Cu regrow hair?","a":"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":[{"cite":"Pickart L, Margolina A. Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data.","where":"Int J Mol Sci, 2018;19:1987 (review)","url":"https://pubmed.ncbi.nlm.nih.gov/?term=Pickart+Margolina+GHK-Cu+2018+review","note":"Review by the peptide's discoverer; declared interest."},{"cite":"Leyden JJ, et al. Skin care benefits of copper peptide containing facial cream.","where":"American Academy of Dermatology meeting, 2002 (abstract)","url":"https://pubmed.ncbi.nlm.nih.gov/?term=copper+peptide+facial+cream+skin+laxity+12+week","note":"Twelve-week facial study; conference abstract, industry-supported."},{"cite":"Mulder GD, et al. Enhanced healing of ulcers in patients with diabetes by topical treatment with glycyl-L-histidyl-L-lysine copper.","where":"Wound Repair Regen, 1994;2:259–269","url":"https://pubmed.ncbi.nlm.nih.gov/?term=Mulder+glycyl-histidyl-lysine+copper+diabetic+ulcers+1994","note":"Small trial of a GHK-Cu gel on diabetic foot ulcers."}],"last_reviewed":"2026-09-02","literature_searched_to":"2026-09-02","changelog":[{"date":"2026-09-02","note":"Full page. Added wound-healing and hair rows, mechanism, regional status and FAQ."},{"date":"2026-09-01","note":"Initial publication."}],"license":"CC BY 4.0 — cite as “LYO Research” with a link.","methodology":"https://lyoresearch.com/methodology"}