GHK-CuWhat the studies show
Three amino acids holding one copper atom, found in human blood in 1973 and studied for skin, wounds and hair — mostly in cells and animals.
5 min read · Animal and lab studies · Updated November 2026
In short
- Name
- GHK-Cu (copper tripeptide-1) (sold by Progression Labs as GHK-Cu)
- Evidence
- Animal and lab studies
- Bottom line
- Cell studies and animal studies with a consistent story, plus small human cosmetic trials. No large placebo-controlled trial in people.
Before you read this
This guide explains what published studies found. That is all it is.
It is not medical advice and it is not instructions for using anything. Where a dose appears, we are reporting what a named study gave the people or animals in it — a fact about the study, not an instruction to you.
The compounds here are not approved by the FDA for use in people and are sold for laboratory research only. A study tells you what happened to the subjects in it; it does not tell you what would happen to you. Talk to a doctor first.
What it is
GHK is a tripeptide — glycine, histidine, lysine — that binds copper, and GHK-Cu is the name for the two together. It was first described in 1973, when a researcher at the University of California found that something in the plasma of young people made old liver tissue behave more like young tissue, and traced the effect to this peptide 1. It occurs naturally in human blood, saliva and urine, and the amount in plasma falls with age: roughly 200 ng/mL at around 20, and about a third of that by 60, according to the researcher who discovered it 2.
The studies below call this molecule GHK-Cu (copper tripeptide-1). Progression Labs sells it as GHK-Cu; the guide uses the store's name and the papers use theirs.
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Collagen and skin cells
The study behind most of the skin claims is from 1988. Human skin fibroblasts — the cells that make collagen — were grown in a dish with GHK-Cu, and they made measurably more collagen, with the effect depending on the amount added 3. Later lab work from the same discoverer's group reported more of other structural proteins too, such as elastin and the glycosaminoglycans that hold water in skin 2.
That is a result in cells, not in a face. The human studies are mostly cosmetic trials of creams containing GHK-Cu, usually small and often funded by the makers; a 2018 review collects them and reports improvements in skin thickness, elasticity and the look of fine lines over 12 weeks, measured by instruments and by dermatologists 2. They are worth knowing about and worth reading with their size in mind.
Wounds
In animals, GHK-Cu applied to wounds sped closure and increased the growth of new blood vessels and the arrival of repair cells; the 2018 review lists studies in rats, mice, rabbits, pigs and dogs 2. The same review describes a mechanism beyond collagen: in gene-expression data from the Broad Institute, GHK changed the activity of a large share of human genes, turning repair and anti-inflammatory genes up and some tissue-destroying enzymes down 2. That is an observation about gene activity in cells, and the review is careful to call it a starting point.
Hair
In mice, GHK-Cu applied to the skin enlarged hair follicles and lengthened the growth phase of the hair cycle, in a 1993 study that compared it with minoxidil 4. Human hair studies of GHK-Cu itself are few; most of what circulates online comes from the mouse work or from products that combine copper peptides with other ingredients.
What is not known
There is no large, independent, placebo-controlled trial of GHK-Cu for any purpose. The cosmetic trials are small, the wound and hair results are in animals, and the gene-expression work is in cells. GHK-Cu is not an approved drug for anything; it is sold as a cosmetic ingredient and, like everything on this site, as a research compound 2.
What these studies are, and aren't
Animal and lab studies. Cell studies and animal studies with a consistent story, plus small human cosmetic trials. No large placebo-controlled trial in people.
Sources
- 1Pickart L, Thaler MM. Tripeptide in human serum which prolongs survival of normal liver cells and stimulates growth in neoplastic liver. Nature New Biology, 1973.
- 2Pickart L, Margolina A. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. International Journal of Molecular Sciences, 2018 (review).
- 3Maquart FX et al. Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+. FEBS Letters, 1988.
- 4Uno H, Kurata S. Chemical agents and peptides affect hair growth. Journal of Investigative Dermatology, 1993.
More in Skin & hair
- AHK-Cu: What the Studies ShowOne amino acid away from GHK-Cu, with one published study behind it: human hair follicles in a dish, in Seoul, in 2007.
- Collagen Peptides: What the Studies ShowNot one molecule but a mixture of fragments of a structural protein, swallowed in grams, with small manufacturer-funded trials on skin behind it.
- GLOW Blend: What the Studies ShowThree peptides with three separate research records — skin cells, rat tendons and animal wounds — and no study of the three together.
- KLOW Blend: What the Studies ShowGLOW plus KPV, a three-amino-acid piece of a hormone studied for gut inflammation in mice — and, as with GLOW, no study of the combination.
- MT-1: What the Studies ShowA tanning peptide from 1980s Arizona that became Scenesse, an approved implant for a rare disease in which sunlight causes burning pain.