Skin & cosmetic
GHK-Cu
Copper Peptide · Copper Tripeptide-1 · 3-aa · Cu²⁺
A copper tripeptide with the strongest cosmetic evidence base of the popular peptides — legal in UK skincare within limits.
Reference status
Editorial research · independent review pending · 3 claims graded
What it is
GHK-Cu is a naturally occurring copper-binding tripeptide. Unlike most peptides on this list, it has a genuine, decades-long cosmetic-science literature behind its topical use, and it is a widely used, legal skincare ingredient.
The gap here is between topical cosmetic use (reasonable evidence) and injectable systemic use (mostly preclinical, and a very different legal picture). We keep those two lanes separate.
The science, graded
What’s claimed — and how strong the evidence behind each claim actually is.
“Improves skin firmness and fine lines (topical)”
Multiple small human studies show improvements in skin appearance and collagen markers. Reasonable for a cosmetic.
Claim-level citation mapping is in progress.
“Supports wound healing and hair follicles”
Strong mechanistic and animal data; human hair-growth evidence is early.
Claim-level citation mapping is in progress.
“Systemic anti-ageing / organ regeneration (injected)”
Interesting lab findings; no controlled human data for injected use.
Claim-level citation mapping is in progress.
Legal and regulatory context
Separate summaries for Great Britain, the United States, and the European Union. These are preliminary research summaries awaiting independent regional review; they are not legal determinations or advice.
Great Britain
As a topical skincare ingredient, GHK-Cu (Copper Tripeptide-1) is legal in the UK cosmetic lane, subject to standard cosmetic-product safety rules. Injectable/systemic use is a different, research-only context.
This is preliminary regulatory research, not a reviewed legal determination or legal advice.
United States
Regional legal and regulatory review required before publication.
This is preliminary regulatory research, not a reviewed legal determination or legal advice.
- FDA's Concerns About Unapproved Drugs · U.S. Food and Drug Administration
- Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks · U.S. Food and Drug Administration
European Union
Regional legal and regulatory review required before publication.
This is preliminary regulatory research, not a reviewed legal determination or legal advice.
- Buying medicines online · European Medicines Agency
What the community says
In skincare communities GHK-Cu is treated as a credible, if pricey, active. In peptide-injection communities it's more experimental. Formulation and pairing (avoid direct vitamin-C mixing) are common topics.
Where they’re talking
- r/SkincareAddictionViewed as evidence-backed for topicals.
- r/PeptidesInjectable use is more debated.
Appears in these stacks
GLOW
Skin quality & appearanceA skin-focused stack built around GHK-Cu, the one peptide here with a real cosmetic evidence base — sometimes combined with recovery peptides.
KLOW
Skin, gut & inflammationAn extended GLOW variant that adds KPV, discussed for its anti-inflammatory profile. Evidence across the components is mixed to preclinical.
References
- 1.Supply unlicensed medicinal products (specials) · MHRA
- 2.FDA's Concerns About Unapproved Drugs · U.S. Food and Drug Administration
- 3.Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks · U.S. Food and Drug Administration
- 4.Buying medicines online · European Medicines Agency