GHK-Cu: a cosmetic topical literature and no trial of the injectable

GHK-Cu is two products with one name. As a cosmetic ingredient it has been in creams since the 1990s. As an injectable "anti-ageing" peptide it has no controlled human study and an FDA safety flag. The regulatory record in 2026 has finally split the two, which makes this page easier to write than it was a year ago.

What it is

GHK is the tripeptide glycyl-L-histidyl-L-lysine, found in human plasma and released from collagen breakdown. It binds copper avidly; GHK-Cu is the copper complex. It was isolated in the 1970s by Loren Pickart, who has authored most of the reviews about it since (PubMed 26236730, 29986520). The reviews report effects on collagen synthesis, wound repair and gene expression in cell culture and animal models.

The evidence

Topical. A 2025 review (PubMed 39963574) summarises the anti-wrinkle literature: small studies of creams and serums measuring skin thickness, elasticity or wrinkle depth over weeks, many run by cosmetic companies, some presented only at meetings, with formulation and skin-penetration problems noted throughout. This is cosmetic-grade evidence: it supports a cosmetic claim, not a medical one.

Injectable. We found no controlled human study of injected or infused GHK-Cu for any purpose, and no pharmacokinetic study. FDA reached the same conclusion.

Regulatory status

FDA placed GHK-Cu for injectable routes in Category 2 on September 29, 2023, and the Category 2 page (content current as of April 22, 2026) now lists it as nominated but withdrawn, retaining the concern: injectable GHK-Cu "may pose risk for immunogenicity due to the potential for aggregation and peptide-related impurities. There are limited data in humans to inform safety-related considerations."

Non-injectable GHK-Cu followed a different path. FDA's category list document (updated May 14, 2026) records that "GHK-Cu (except for injectable routes of administration)" was removed from Category 1 on April 22, 2026 because the nominators withdrew, and was added back after one nominator clarified on May 5, 2026 that it was withdrawing only the injectable route. FDA states it intends to consult the Pharmacy Compounding Advisory Committee on GHK-Cu before the end of February 2027.

So as of September 2026: topical or other non-injectable GHK-Cu is in Category 1 (FDA does not intend to act against compounding with it while it evaluates, if the other 503A conditions are met); injectable GHK-Cu is not in Category 1, is not on the bulks list, and carries a published safety concern. Our 503A bulks list explainer covers what the categories mean.

Safety signals

For the injectable: FDA's immunogenicity concern and the absence of human data. Copper itself is a further consideration for a parenteral product that a topical cream does not raise; no published human study has examined systemic copper exposure from injected GHK-Cu.

Grade: D + X (injectable)

D because there is no controlled human study of the injectable form. X because FDA has published a safety concern for that route. The topical cosmetic use is not graded on a medical scale because it does not make a medical claim; if a seller's page for injectable GHK-Cu cites skin-cream studies, that is the substitution described in how to read a peptide study.