GHK-Cu, the copper tripeptide, has two placebo-controlled studies on hair in humans today. In a 2016 study the number of scalp hairs rose after six months by 52.6 and 71.5 in two peptide groups, and by 9.6 in the placebo group. In a 2026 study a serum with 2 percent GHK-Cu increased the number and thickness of eyebrow hairs after 12 weeks. On top of that come studies on hair follicles in the laboratory and in animals. Below we collect all these results and explain how to read them.
What is GHK-Cu?
GHK is a short peptide of three amino acids: glycine, histidine and lysine. It occurs naturally in the human body, among other places in the blood. It binds a copper ion very easily, and is then called GHK-Cu or copper tripeptide.
The best-described action of GHK-Cu concerns the skin and wound healing. A 2018 review in the International Journal of Molecular Sciences lists stimulation of collagen and elastin production, the formation of new blood vessels and support for fibroblasts, the cells of connective tissue. This is described in more detail in the guide on GHK-Cu and studies on skin and healing.
Why might a copper peptide act on hair?
A hair grows from a hair follicle. At its base lies the dermal papilla, a group of specialised fibroblasts that control hair growth. When these cells divide efficiently, the hair grows for longer and is thicker.
Copper tripeptides stimulate skin fibroblasts to divide and increase the production of vascular growth factor. These are two reasons why researchers began testing them on hair follicles. The authors of the 2016 study also write that GHK without copper may give effects similar to GHK-Cu.
What did studies on hair follicles in the laboratory show?
In 2007 dermatologists from Seoul National University published a study on human hair follicles grown outside the body. They used a close relative of GHK-Cu, the copper tripeptide AHK-Cu, in which alanine replaces glycine.
- Hair length: follicles in contact with the peptide lengthened faster.
- Papilla cells: divided faster at very low peptide concentrations.
- Cell death: signals that lead a cell to die decreased.
The authors conclude that the copper tripeptide supports follicle growth because it stimulates division of papilla cells and protects them from dying. It is a laboratory result, not one from a human scalp, but it shows the mechanism.
What did animal studies show?
In 1993 researchers from the primate research centre in Wisconsin described in the Journal of Investigative Dermatology how several agents act on hair growth. A copper-binding peptide called PC1031 enlarged hair follicles on the backs of rats. The effect was similar to topical minoxidil, a substance known from the treatment of hair loss.
The same paper describes that minoxidil and similar agents work by stimulating division of follicle cells. The follicle then changes from a small, vellus one into a large one that produces a thick hair. The copper peptide gave a similar picture in rats.
What did the study on the scalp in men show?
The strongest scalp data come from Kyungpook National University in Korea. In 2016 Annals of Dermatology published a study in 45 men with male pattern hair loss. The researchers combined GHK with 5-aminolevulinic acid in one preparation called ALAVAX.
Every evening before sleep, participants sprayed one of three liquids on the scalp for six months. Hairs were counted with a scalp camera in a circle 1 cm in diameter on the forehead, always in the same place.
| Group | Increase in hair count after 6 months | Good or very good rating by participants |
|---|---|---|
| ALAVAX 100 mg/ml | 52.6, significantly more than at the start | 26.7 percent |
| ALAVAX 50 mg/ml | 71.5, significantly more than at the start | 14.3 percent |
| Placebo | 9.6 | 7.1 percent |
The difference in the rate of increase between the 50 mg/ml group and placebo was statistically significant. No adverse effects occurred in any group. Hair length and thickness after six months did not differ between groups.
What did the 2026 eyebrow study show?
In May 2026 a study was published in which 18 healthy people aged 18 to 40 applied a serum to their eyebrows. One eyebrow received a serum with 2 percent GHK-Cu, and the other the same serum without the peptide. Neither participants nor researchers knew which eyebrow got which preparation.
The serum was applied twice a day for 12 weeks. On the GHK-Cu side the number of eyebrow hairs rose significantly from baseline, while on the side without the peptide it did not change. Hair thickness also increased. Photo assessment and participant satisfaction were higher on the peptide side throughout the study. There were no serious adverse effects or allergic reactions.
A 2026 review in Pharmaceutics calls this study the strongest new controlled signal for GHK-Cu in cosmetics. It is a good result, because comparing two eyebrows of the same person rules out many differences between people.
How strong are these data?
Two placebo-controlled studies in humans are more than most peptides have, but still few. Both were small, run at a single centre and lasted three to six months.
- Scalp, 2016: the preparation combined GHK with a second substance, so the share of the peptide alone cannot be separated.
- Eyebrows, 2026: pure GHK-Cu in a serum, but only 18 people and eyebrows instead of the scalp.
- Laboratory and animals: related copper peptides, AHK-Cu and PC1031, not GHK-Cu itself.
A 2026 systematic review lists androgenetic alopecia among the uses for which the authors propose further clinical trials. They also point to microneedles as a way to improve absorption of the peptide through the skin, because GHK-Cu penetrates the epidermis poorly.
How does GHK-Cu compare with minoxidil?
Minoxidil and finasteride are approved medicines for male pattern hair loss with large studies. GHK-Cu has no such studies and is not a medicine. In the 1993 rat study, however, the copper peptide gave an effect similar to topical minoxidil.
In practice GHK-Cu more often enters studies as an addition than as a replacement. A 2018 report of four cases combined a fractional laser, topical finasteride, growth factors and 1 percent copper peptide. All four people had improved hair density, but without a comparison group it is not known how much the peptide itself contributed.
Where to buy GHK-Cu and how much does it cost?
The shop has copper tripeptide GHK-Cu 100 mg Bio-Peptide for 40 EUR, in stock. It is a freeze-dried powder in a vial, ready to be dissolved. How to prepare a solution from it is shown in the guide on how to reconstitute a peptide.
Everything about the molecule is collected on the GHK-Cu page, and studies on collagen are described in the guide on GHK-Cu and collagen. The products in the shop are material for laboratory research, not a medicine. Hair loss is diagnosed and treated by a dermatologist.
Frequently asked questions
Does GHK-Cu help with hair loss?
In a 2016 study in 45 men, a preparation with GHK increased hair count after six months by 52.6 and 71.5, and placebo by 9.6. The preparation also contained 5-aminolevulinic acid.
Does GHK-Cu work on eyebrows?
In a 2026 study a serum with 2 percent GHK-Cu increased the number and thickness of eyebrow hairs after 12 weeks. The eyebrow without the peptide did not change.
How long does GHK-Cu take to show results on hair?
In the eyebrow study the difference was clearest after 12 weeks. In the scalp study hairs were counted after 1, 3 and 6 months.
Does GHK-Cu for hair have side effects?
Neither of the placebo-controlled studies described serious adverse effects or allergic reactions.
How much does GHK-Cu cost in the shop?
Copper tripeptide GHK-Cu 100 mg Bio-Peptide costs 40 EUR and is in stock.
Sources
- Lee WJ, Sim HB, Jang YH et al. Efficacy of a Complex of 5-Aminolevulinic Acid and Glycyl-Histidyl-Lysine Peptide on Hair Growth. Annals of Dermatology, 2016, 28(4): 438-443. https://doi.org/10.5021/ad.2016.28.4.438
- Bo SL, Nararatwanchai T, Supornpun N et al. The efficacy of 2% copper peptide (GHK-Cu) serum for eyebrow hypotrichosis: A randomized, double-blind, vehicle-controlled, split-face comparative study. Procedia of Multidisciplinary Research, 2026, 4(5). https://so09.tci-thaijo.org/index.php/PMR/article/view/9318
- Pyo HK, Yoo HG, Won CH et al. The effect of tripeptide-copper complex on human hair growth in vitro. Archives of Pharmacal Research, 2007, 30(7): 834-839. https://doi.org/10.1007/BF02978833
- Uno H, Kurata S. Chemical agents and peptides affect hair growth. Journal of Investigative Dermatology, 1993, 101(1 Suppl): 143S-147S. https://doi.org/10.1111/1523-1747.ep12363275
- Pickart 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, 19(7): 1987. https://doi.org/10.3390/ijms19071987
- Mateescu DM, Gavrilescu DM, Mincioaga RI et al. GHK-Cu as a Bioactive Metallopeptide and Drug-Delivery Cargo. Pharmaceutics, 2026, 18(9): 1077. https://doi.org/10.3390/pharmaceutics18091077
- Najafi N, Maatouk H, Vardanyan KG et al. A Systematic Review of the Mechanisms and Therapeutic Applications of GHK-Cu in Topical Microneedle Delivery. Archives of Internal Medicine Research, 2026, 9(3): 269-293. https://doi.org/10.26502/aimr.0255
- Bertin ACJ, Vilarinho A, Junqueira ALA. Fractional non-ablative laser-assisted drug delivery leads to improvement in male and female pattern hair loss. Journal of Cosmetic and Laser Therapy, 2018, 20(7-8): 391-394. https://doi.org/10.1080/14764172.2017.1418516