GHK-Cu (Copper Tripeptide)

What it is

GHK consists of three amino acids, glycine, histidine and lysine, and binds copper so tightly that in the body it is present mainly as GHK-Cu. It was discovered in 1973 by Pickart as a component of human albumin that caused old liver tissue to produce proteins again like young tissue. It is found in blood plasma, saliva and urine.

According to current understanding, GHK is a so-called matricryptin: a fragment that is released from connective tissue proteins such as collagen during injuries and signals to the body that repair is needed. As a cosmetic ingredient, it is contained in many anti-wrinkle products under the name copper tripeptide-1. In the biohacking scene it is also injected under the skin, in the hope of an effect throughout the body.

How it works

GHK-Cu acts at several points at once. It supplies copper, the cofactor of lysyl oxidase, which cross-links collagen and elastin and gives tissue its firmness. In skin cells it stimulates the formation of collagen, elastin, dermatan sulfate, chondroitin sulfate and decorin and at the same time regulates the enzymes that break down old connective tissue. It attracts immune and vascular cells to the site of an injury and promotes the formation of new blood vessels.

The gene level is often cited. In the Connectivity Map, a database of gene expression profiles of human cell lines, GHK changed the activity of 31.2 percent of the genes recorded by at least half. Pickart and colleagues speak of at least 4,000 genes, including 47 upregulated DNA repair genes. This is an interesting finding, but it comes from cell lines, not from human skin after application.

Cream, gel and injection

The distinction by route of administration is important. On the skin, the peptide has to get past the stratum corneum, and according to a 2025 review, the published data on exactly this are insufficient. That is why there is a lot of experimentation with microneedles and carrier systems, which in the laboratory and on pig skin deliver GHK-Cu into the skin considerably better.

On open wounds this question does not arise, and that is where the strongest human study so far lies. With injection, finally, a completely different idea is at stake, namely systemic effects on skin, hair, joints or inflammation throughout the body. This idea rests on animal studies in which GHK promoted wound healing at distant sites even after administration under the skin, not on data in humans.

Copper as a building block

Copper is an essential trace element that the body needs for connective tissue, energy metabolism and blood formation. Too much of it, however, harms above all the liver. The Office of Dietary Supplements of the US health agency NIH sets the tolerable upper intake level for adults at 10 milligrams per day and derives it from liver damage. How much copper gets into the body from a cream has been little studied. How much copper an injection of gray market product actually contains, by contrast, is not controlled, and that is exactly what makes injection an open question from this angle too.

What the studies show

Mulder et al. 1994 — diabetic foot ulcers

Multicenter, randomized, placebo-controlled, blinded evaluation. GHK-Cu gel plus standard wound care versus gel without active ingredient. Median wound closure 98.5 versus 60.8 percent, infections 7 versus 34 percent. The abstract does not state the number of participants; no approval followed.

Cosmetic studies around 2002 — face and eyes

Face cream in 71 women, eye cream in 41 women versus placebo and vitamin K, another study with 67 women aged between 50 and 59, each over 12 weeks. Fewer wrinkles and denser, firmer skin are reported. Published as conference contributions and reports, summarized in reviews by the discoverer.

Mateescu et al. 2026 — the current evidence map

Systematic analysis up to August 2026. Preclinically consistent effects on matrix, wound healing, inflammation and new blood vessel formation; clinically thin data. A study with 13 participants after laser treatment was negative on objective measurements, a split-face study with 18 participants on the eyebrows positive. A phase 2 trial on acute wounds is still recruiting.

Where the data stop

The image of one of the best-supported anti-aging substances only partly withstands close scrutiny. A 2026 systematic review analyzed 64 papers and describes the human literature as thin and fragmentary; most randomized trials are small and limited to face creams. Many of the frequently cited cosmetic studies are conference contributions or industry reports without peer review, summarized by the discoverer of the peptide himself. A second review therefore calls GHK-Cu promising but clinically unproven.

For injection there is not a single human study, neither on efficacy nor on safety. The statement that GHK-Cu resets more than 4,000 genes to young is also based on cell line data. The often-cited comparison with minoxidil for hair growth could not be substantiated in the sources reviewed.

Status, approval and legal

As a cosmetic ingredient, GHK-Cu can be freely marketed in Germany and the EU and is contained in numerous serums and creams. It is not approved as a medicine anywhere, not even as a wound gel. Injectable products are sold as research peptides. The FDA lists GHK-Cu for injection among the substances whose nomination for compounding was withdrawn, and names a possible immune risk from aggregation and impurities. Non-injectable GHK-Cu, by contrast, is again under FDA review for compounding according to its list of May 14, 2026; its expert panel plans to hear the matter by the end of February 2027. It is not on the WADA prohibited list. We do not give dosage information for injection.

Safety

On the skin, GHK-Cu has been used in cosmetics for decades without any documented accumulation of serious side effects, but systematic safety studies are missing. With injection the situation is different: the FDA sees an immune risk and limited human data, and a not yet peer-reviewed analysis of 6,441 gray market samples from 14 peptides, including GHK-Cu, found quality defects in 41.6 to 71.1 percent and endotoxin in 15 percent. Every dose brings copper into the body. People with Wilson’s disease, a hereditary disorder of copper excretion, should avoid additional sources of copper. Data on pregnancy and breastfeeding are missing.

Sources

• Mulder et al., Wound Repair and Regeneration 1994 (randomized, placebo-controlled)
• Pickart, Vasquez-Soltero & Margolina, BioMed Research International 2015
• Pickart & Margolina, International Journal of Molecular Sciences 2018
• Pickart, Vasquez-Soltero & Margolina, Oxidative Medicine and Cellular Longevity 2012
• Mateescu et al., Pharmaceutics 2026
• Najafi et al., Archives of Internal Medicine Research 2026
• Mortazavi et al., BioImpacts 2025
• FDA, bulk drug substances that may present significant safety risks, as of April 22, 2026
• NIH Office of Dietary Supplements, Copper Fact Sheet
• FDA, Bulk Drug Substances Nominated Under Section 503A, as of May 14, 2026