What it is
GHK-Cu is a tiny protein fragment, just three amino acids long, that carries a copper atom. It occurs naturally in human blood, saliva and urine, and blood levels fall with age. The “Cu” is the chemical symbol for copper; the copper is what gives the powder and solutions their blue colour.
It is by far the most common of the peptides on this site in everyday products: it has been an ingredient in skin creams and hair products for decades, at low concentrations, where it is regulated as a cosmetic rather than a drug. The recent interest is in stronger forms, including injectable ones, and there the evidence and the regulatory position are very different. No injectable or drug product containing GHK-Cu is approved anywhere.
GHK (glycyl-L-histidyl-L-lysine, C14H24N6O4, 340.4 g/mol) binds copper(II) with high affinity (log K about 16) through the glycine α-amino nitrogen, the histidine imidazole and the deprotonated amide nitrogen, forming the 1:1 complex GHK-Cu (C14H22CuN6O4, about 401.9 g/mol). Plasma concentration in young adults is about 200 ng/mL, falling to roughly 80 ng/mL by age 60 (Pickart’s figures). GHK is thought to be released by proteolysis of extracellular-matrix proteins such as collagen α2(I) and SPARC at injury sites.
Reported activities in cell and animal models include stimulation of collagen, elastin and glycosaminoglycan synthesis by fibroblasts, modulation of matrix metalloproteinases and their inhibitors, chemoattraction of immune and endothelial cells, and antioxidant effects partly attributable to copper delivery to superoxide dismutase. A 2018 review by Pickart and Margolina compiles gene-expression (Connectivity Map) data suggesting broad transcriptional effects. Human pharmacokinetics after injection have not been published.
Who made it and when
Loren Pickart identified the peptide in 1973 while working on why old blood plasma made liver cells behave old and young plasma made them behave young; the active factor turned out to be this three-amino-acid fragment bound to copper. Pickart later founded companies that licensed it as a cosmetic ingredient, and most of the review literature about it is written by him. Clinical work in the 1990s tested it in wound-healing creams and gels. In 2026 a company called Hudson Biotech posted a registry entry for a 0.1% gel on small skin wounds in China; the same sponsor posted a TB-500 entry that describes itself as fictional, so this one is not counted as a confirmed trial.
Pickart and Thaler reported the tripeptide in Nature New Biology in 1973 as a serum factor that prolonged survival of hepatocytes in culture. The copper complex was characterised over the following decade. Cosmetic patents under Pickart and licensees (Procyte Corporation, later Photomedex) covered topical formulations; those patents have expired and are not listed here because current holders could not be verified. The only registry entry for GHK-Cu as a drug is NCT07437586 (Phase 2, topical gel), posted in 2026 by Hudson Biotech, whose TB-500 entry NCT07487363 describes itself as “a fictional study”; it is not listed as a trial on this page. Earlier published clinical studies of GHK-Cu creams and gels in diabetic ulcers and photoaged skin are small, mostly industry-run and not registered.
What the data say
There is decent evidence that low-concentration GHK-Cu creams improve the appearance of aged skin and that gels can help wound healing, from small trials run mostly by the companies selling it. There is a large amount of test-tube and animal data suggesting it drives collagen production and tissue repair. What there is not is any controlled human study of GHK-Cu injections, and no published data on how much copper it delivers into the body when injected or what that does. The only registry entry, for a gel on small biopsy wounds, comes from a sponsor whose other entries include a self-described fictional one, and it has not reported.
Topical human data: small controlled studies from the 1990s and 2000s reported improved skin density, reduced fine lines and increased collagen in photoaged skin, and improved closure of diabetic and other chronic wounds with GHK-Cu gel; these are summarised in Pickart’s reviews rather than in independent meta-analyses, and most are not registered or are unpublished company reports. The 2026 registry entry NCT07437586 describes a Phase 2 split-wound design with 0.1% w/w gel; its genuineness could not be confirmed and no results have been posted.
Preclinical: in vitro, GHK-Cu increases fibroblast collagen and decorin synthesis, dermal fibroblast proliferation and endothelial migration; in rodent and porcine wound models, topical GHK-Cu increased granulation tissue and angiogenesis. Systemic administration data are limited to a few rodent studies (for example lung injury and bone models). No human injectable trial, pharmacokinetic study or systematic safety data exist. FDA’s 2023 listing stated there were “limited data in humans” for injectable use.
Regulatory picture
Three separate facts. Approval: GHK-Cu is not an approved drug anywhere, but it is a permitted cosmetic ingredient, so creams containing it are legal to sell as cosmetics provided they make no drug claims. Compounding: in September 2023 the FDA put injectable GHK-Cu in Category 2, the group of substances it said raise significant safety risks, so pharmacies compounding with it could face FDA action; it cited immunogenicity risk and lack of human data. By April 2026 the FDA’s page listed it as withdrawn from that category by its nominator. Unlike BPC-157, TB-500 and KPV, GHK-Cu was not on the July 2026 advisory committee agenda. In May 2026 the FDA put GHK-Cu for non-injectable uses back under evaluation and said it intends to bring GHK-Cu before the same committee by the end of February 2027. Enforcement: no FDA warning letters specific to GHK-Cu were found.
Approval: none. No IND-stage programme could be verified. Topical cosmetic use falls under the FD&C Act cosmetic provisions and INCI listing as copper tripeptide-1; that does not constitute drug approval.
Compounding: “GHK-Cu (for injectable routes of administration)” was placed in Category 2 of the interim 503A policy on 2023-09-29, with FDA citing aggregation-related immunogenicity, peptide impurities and limited human data. FDA’s page updated 2026-04-22 lists it among substances withdrawn from Category 2 by the nominators. It is not on the 503A bulks list (21 CFR 216.23) and was not among the substances reviewed by the Pharmacy Compounding Advisory Committee on 2026-07-23. FDA’s 503A categories list updated 2026-05-14 returned “GHK-Cu (except for injectable routes of administration)” to Category 1 after a nominator clarified it had meant to withdraw only the injectable nomination, and states that FDA intends to consult the committee on GHK-Cu before the end of February 2027. This article therefore records the compounding status as unknown. The Category 2 listing never applied to topical cosmetic products.
