GHK-Cu is a small copper peptide: the three amino acids glycine, histidine and lysine (Gly-His-Lys, or GHK) bound to a copper(II) ion. Unlike most “research peptides,” GHK occurs naturally in the human body. It was first isolated from human plasma in 1973, and its plasma level falls with age.

GHK-Cu is widely used in skin and hair cosmetics, and injectable versions are sold online for skin, healing and “recovery.” Its laboratory and animal record is large, but its human evidence is small: a few topical wound trials from the 1990s with mixed results, and small cosmetic studies, many of them industry conference reports. No controlled trial has tested injected GHK-Cu in people, and it is not an approved drug.

This page summarizes what the laboratory studies, the clinical trials and regulators report. It is for education only and is not medical advice.

Property	Detail
Class	Naturally occurring copper-binding tripeptide complex
Other names	Copper tripeptide-1 (cosmetic INCI name); prezatide copper; GHK copper
Peptide (GHK)	Glycyl-L-histidyl-L-lysine, C₁₄H₂₄N₆O₄, 340.38 g/mol (PubChem)
Natural level in plasma	About 200 ng/mL at age 20, falling to about 80 ng/mL by age 60 (industry-authored review)
Studied routes in people	Topical only (gels, creams, serums)
Human trials	Small topical wound and cosmetic studies; none of injected GHK-Cu
Half-life	No published human data; GHK was rapidly broken down after IV dosing in rats
Approval status	Not an approved drug; a GHK-Cu wound gel was cleared as a device in 1996
FDA compounding	Injectable GHK-Cu was placed on FDA’s safety-risk list; nomination later withdrawn
WADA status	Not named; S0 and S2.3 catch-all clauses may apply

What it is

GHK is a tripeptide (a chain of three amino acids). PubChem lists it as glycyl-L-histidyl-L-lysine, formula C₁₄H₂₄N₆O₄, molecular weight 340.38 g/mol (PubChem CID 73587). The copper complex has a separate record under the name prezatide copper (CAS 89030-95-5), with “copper tripeptide-1” as its cosmetic ingredient (INCI) name (PubChem CID 71587328).

Loren Pickart and Melvin Thaler first described GHK in 1973 as a factor in human serum that prolonged the survival of normal liver cells and stimulated growth in neoplastic (tumor) liver tissue (Pickart and Thaler, Nat New Biol 1973). In 1980 the same group reported that the peptide co-purified with roughly equal molar amounts of copper, readily formed copper complexes, and increased copper uptake into cultured liver cancer cells (Pickart et al., Nature 1980).

How the copper binds

GHK binds copper(II) with an affinity similar to the copper-transport site on albumin, the main protein in blood (Pickart, J Biomater Sci Polym Ed 2008). In plasma, GHK is most concentrated in the albumin-rich fraction. A 2021 study showed that copper-GHK forms mixed (ternary) complexes with human serum albumin through histidine side chains on the albumin molecule (Bossak-Ahmad et al., Inorg Chem 2021). This suggests albumin may help carry GHK-Cu in the blood.

A 2026 review stresses that “GHK-Cu” is not a single fixed substance. The form of the copper complex depends on pH, the copper-to-peptide ratio and other molecules present. Most published studies and products do not report how much of the copper is truly bound versus loosely held (“labile”) (Mateescu et al., Pharmaceutics 2026).

GHK-Cu and AHK-Cu

Feature	GHK-Cu	AHK-Cu
Sequence	Gly-His-Lys + Cu(II)	Ala-His-Lys + Cu(II)
Origin	Naturally occurring human peptide	Synthetic analog
Published research	Decades of lab and animal work; small human topical trials	One primary hair-follicle lab study
Human trials	Topical wound and cosmetic studies	None

The synthetic analog is covered on the AHK-Cu page.

How it works in the body

Proposed mechanisms

Most mechanistic data come from cell culture and animal wound models. A review by Pickart, whose listed affiliation is the company Skin Biology, lists effects including attraction of repair cells, anti-inflammatory and antioxidant actions, and increased production of collagen, elastin, vascular endothelial growth factor (VEGF, a signal for new blood vessels) and other growth factors (Pickart, J Biomater Sci Polym Ed 2008). A later review by the same group adds gene-expression data from cell lines (Pickart and Margolina, Int J Mol Sci 2018).

Independent reviewers agree that preclinical data consistently point to effects on tissue remodeling, skin repair, inflammation and blood vessel growth. They also note that few studies separate the effects of the intact complex from those of free GHK or free copper (Mateescu et al., Pharmaceutics 2026).

Absorption, half-life and breakdown

No study has measured the half-life of GHK-Cu in people, by any route. The available data are:

Rats, intravenous. A 1997 assay study gave GHK intravenously to rats and found it was rapidly broken down to the dipeptide histidyl-lysine, which was itself eliminated rapidly. The abstract does not report a half-life value (Endo et al., J Chromatogr B 1997).
Human skin in the lab. In isolated human skin in diffusion cells, copper applied as GHK-Cu (0.68% copper solution) crossed dermatomed skin with a permeability coefficient of 2.43 × 10⁻⁴ cm/h. Over 48 hours, about 136 µg/cm² of copper passed through and about 82 µg/cm² stayed in the skin (Hostynek et al., Inflamm Res 2010). This measured copper, not intact peptide.

The 2026 Pharmaceutics review states that free GHK is “expected” to have a short half-life because blood and tissue enzymes cut it into smaller pieces. Released copper is taken up by albumin and other carriers and cleared mainly through the liver and bile (Mateescu et al., Pharmaceutics 2026). Half-life figures quoted online for injected GHK-Cu are not based on published human measurements.

Regulatory status

No approved drug. We found no FDA- or EMA-approved drug containing GHK-Cu.
A wound dressing cleared as a device. FDA’s 510(k) database lists “Iamin Gel Wound Dressing” from ProCyte Corp., cleared on February 5, 1996 (FDA 510(k) K953853). Iamin 2% Gel from ProCyte is a GHK-Cu product (Canapp et al., Vet Surg 2003). A device clearance as a dressing is not drug approval and does not cover injection.
Compounding. FDA placed GHK-Cu “for injectable routes of administration” on its list of bulk substances that may present significant safety risks, citing possible immune reactions (immunogenicity) from aggregation and peptide-related impurities, and “limited data in humans.” The nominator later withdrew the nomination, and FDA lists it under “nominated but withdrawn,” alongside BPC-157 (FDA).
Cosmetics. Copper tripeptide-1 is an established cosmetic ingredient name, and products using it are sold as cosmetics (PubChem CID 71587328).

What the research shows

Chronic wounds in people

Two randomized topical trials from the early 1990s tested GHK-Cu on chronic ulcers. They reached opposite conclusions.

Trial	Design	Treatment	Main result
Diabetic foot ulcers (Mulder et al., Wound Repair Regen 1994)	Multicenter, randomized, evaluator-blinded, vehicle-controlled	Iamin Gel (GHK-Cu) plus standardized wound care	Median plantar ulcer closure 98.5% vs 60.8% with vehicle (p under 0.05)
Venous leg ulcers (Bishop et al., J Vasc Surg 1992)	Randomized, evaluator-blinded; 86 evaluable patients	0.4% GHK-Cu cream vs 1% silver sulfadiazine vs inert vehicle	No difference between GHK-Cu and vehicle; silver sulfadiazine reduced ulcer size more

In the diabetic ulcer trial, the benefit was larger in plantar ulcers over 100 mm² (median closure 89.2% vs −10.3% with vehicle, p under 0.01). Infection of plantar ulcers treated right after debridement was lower with GHK-Cu (7% vs 34%, p under 0.05). The abstract does not report the number of patients enrolled. The trial was not followed by a drug approval.

Skin aging and cosmetic use

The only peer-reviewed randomized trial with objective skin outcomes we found was small. Patients who had CO₂ laser resurfacing around the mouth were randomized to skin-care regimens with or without GHK-Cu; 13 completed the study (Miller et al., Arch Facial Plast Surg 2006):

Computer analysis and blinded evaluators found no difference in how fast redness resolved.
Wrinkles and overall skin quality improved in all patients, with no difference between groups.
Patients using GHK-Cu rated their skin quality improvement higher on a questionnaire (p = 0.04).

Other cosmetic results are cited mainly through a review written by GHK’s discoverer and a colleague, both listed at the company Skin Biology (Pickart and Margolina, Int J Mol Sci 2018). The first two studies below were conference presentations at a 2002 dermatology meeting:

Study (as summarized in the review)	Participants	Reported result
GHK-Cu facial cream, 12 weeks	71 women with photoaging	Increased skin density and thickness; reduced laxity and fine lines
GHK-Cu eye cream, 12 weeks	41 women with photodamage	Better than placebo and vitamin K cream on lines and wrinkles
Thigh skin cream, 12 weeks	Women (number not given)	Collagen production improved in 70%, vs 50% with vitamin C and 40% with retinoic acid
GHK-Cu in nano-lipid carrier, 8 weeks, randomized double-blind	Female volunteers	Wrinkle volume 55.8% lower and depth 32.8% lower than control serum

A 2026 systematic review in aesthetic medicine found 20 eligible studies of GHK-Cu, of which 18 were preclinical and only 2 were randomized controlled trials. It concluded that findings were limited by methodological variability and few well-designed clinical trials (Mokhtar et al., Aesthet Surg J 2026). The 2026 Pharmaceutics review described the historical cosmetic reports as “small or incompletely characterized” (Mateescu et al., Pharmaceutics 2026).

Hair

The same review describes a 2026 randomized, double-blind, vehicle-controlled split-face study of a 2% GHK-Cu serum for sparse eyebrows in 18 healthy participants. The treated side showed improved hair count and diameter at 12 weeks, with no serious adverse events. The review notes it was a small single-center study with chemically undercharacterized test material (Mateescu et al., Pharmaceutics 2026). We found no controlled trial of GHK-Cu for scalp hair loss.

Animal wound studies

Animal studies are the strongest part of the evidence, but they do not show effects in people:

Rats, wound chambers. Repeated injections of GHK-Cu into implanted wound chambers raised collagen, protein, DNA and glycosaminoglycan content in a concentration-dependent way. A control tripeptide had no effect (Maquart et al., J Clin Invest 1993).
Rats, ischemic wounds. In 24 rats, topical Iamin 2% Gel reduced wound area faster than no treatment, and on some days faster than its vehicle. Wound area had shrunk by 64.5% with GHK-Cu, 45.6% with vehicle and 28.2% with no treatment by day 13 (Canapp et al., Vet Surg 2003).

Muscle, tendon and injury recovery

GHK-Cu is promoted for sports injury recovery, but we found no human trial of any route on muscle, tendon, ligament or performance outcomes. A 2026 UCLA scoping review of six popular peptides, including GHK-Cu, concluded that claimed benefits for musculoskeletal recovery “remain unsubstantiated by current human trials” (Tewari et al., Am J Sports Med 2026). A 2026 review of gray-market peptides in sports medicine, which included GHK-Cu, noted that rigorous human safety data are scarce (Mendias and Awan, Sports Med 2026).

Ongoing research

A phase 2 randomized, double-blind, vehicle-controlled trial (CuHeal) is testing a 0.1% GHK-Cu gel applied once daily for 14 days on standardized punch-biopsy wounds in healthy adults, with an estimated 60 participants. It was recruiting as of this writing and had posted no results (ClinicalTrials.gov NCT07437586).

Side effects and risks

Limited human safety data

The topical trials above did not report rates of side effects in their abstracts. The 2026 eyebrow study reported no serious adverse events. There are no published human safety data for injected GHK-Cu, and its safety in pregnancy, in children and with other drugs is unknown. The 2026 Pharmaceutics review states that no validated human no-adverse-effect level, skin exposure limit or safe limit for loosely bound copper exists for GHK-Cu (Mateescu et al., Pharmaceutics 2026).

Injected products

FDA’s concerns about compounded injectable GHK-Cu were possible immunogenicity from aggregation and peptide-related impurities, and limited human data (FDA). Products sold online as “research chemicals” are outside regulated manufacturing, so their identity, purity, copper content and sterility are not verified.

Copper

Copper is a redox-active metal. The 2026 Pharmaceutics review names cumulative copper burden as the main long-term concern with chronic or large-area topical use or repeated injection. It calls for testing of liver and, at high exposure, nervous system copper accumulation, and for testing of skin sensitization (allergy) to copper (Mateescu et al., Pharmaceutics 2026). These are proposed safety studies, not observed harms, because the studies have not been done.

Blood vessel growth

GHK-Cu is reported to promote angiogenesis (new blood vessel growth) in preclinical models. The same review notes that this may be undesirable in tumors, proliferative retinopathy (abnormal vessel growth in the eye) or vascular malformations, and that any systemic or injectable use would need specific safety testing for this (Mateescu et al., Pharmaceutics 2026). GHK was originally described as stimulating growth in neoplastic liver tissue (Pickart and Thaler, Nat New Biol 1973); what this means in people is unknown.

Legal status and use outside medicine

US controlled substances. GHK-Cu is not an anabolic steroid and is not named in Schedule III (21 CFR 1308.13).
Sport. GHK-Cu is not named on the WADA list. Class S0 prohibits at all times any pharmacological substance not covered elsewhere and “with no current approval by any governmental regulatory health authority for human therapeutic use.” Class S2.3 also prohibits growth factors and growth factor modulators affecting, among other things, vascularisation or regenerative capacity (WADA 2026 Prohibited List). We found no specific WADA ruling on GHK-Cu.

Key takeaways

A natural human copper peptide. GHK occurs in human plasma, binds copper with an affinity similar to albumin, and its plasma level falls with age.
Strong lab and animal data. Rat and rabbit studies show faster wound closure and more collagen in wounds, but these results do not establish effects in people.
Mixed, small human trials. A 1994 trial reported faster diabetic ulcer closure, a 1992 venous ulcer trial found no benefit over vehicle, and a 13-patient laser trial found no objective skin advantage.
No human data for injection. There are no controlled trials of injected GHK-Cu and no human half-life data. Claims for muscle, tendon or injury recovery are unsupported by human studies.
Unapproved and unregulated. It is not an approved drug; FDA flagged injectable compounded GHK-Cu for possible immune and impurity risks. See AHK-Cu for its synthetic analog.

Sources

Pickart L, Thaler MM. Tripeptide in human serum which prolongs survival of normal liver cells and stimulates growth in neoplastic liver. Nat New Biol. 1973;243(124):85–87. PubMed.
Pickart L, Freedman JH, Loker WJ, et al. Growth-modulating plasma tripeptide may function by facilitating copper uptake into cells. Nature. 1980;288(5792):715–717. PubMed.
Pickart L. The human tri-peptide GHK and tissue remodeling. J Biomater Sci Polym Ed. 2008;19(8):969–988. PubMed.
Pickart L, Margolina A. Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data. Int J Mol Sci. 2018;19(7):1987. PubMed; PMC.
Bossak-Ahmad K, Bal W, Frączyk T, Drew SC. Ternary Cu(2+) complexes of human serum albumin and glycyl-l-histidyl-l-lysine. Inorg Chem. 2021;60(22):16927–16931. PubMed.
National Center for Biotechnology Information. Glycyl-L-histidyl-L-lysine, PubChem CID 73587. PubChem.
National Center for Biotechnology Information. Prezatide copper, PubChem CID 71587328. PubChem.
Mateescu DM, Gavrilescu DM, Mincioaga RI, et al. GHK-Cu as a bioactive metallopeptide and drug-delivery cargo: coordination chemistry, formulation science, therapeutic evidence, and a translational roadmap. Pharmaceutics. 2026;18(9):1077. PubMed; PMC.
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Mulder GD, Patt LM, Sanders L, et al. Enhanced healing of ulcers in patients with diabetes by topical treatment with glycyl-l-histidyl-l-lysine copper. Wound Repair Regen. 1994;2(4):259–269. PubMed.
Bishop JB, Phillips LG, Mustoe TA, et al. A prospective randomized evaluator-blinded trial of two potential wound healing agents for the treatment of venous stasis ulcers. J Vasc Surg. 1992;16(2):251–257. PubMed.
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Mokhtar J, Mohamad B, Haddad J, et al. The regenerative potential of GHK-Cu in aesthetic medicine. Aesthet Surg J. Published online August 20, 2026. PubMed.
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Hudson Biotech. Topical GHK-Cu gel for acute skin wound healing (CuHeal). ClinicalTrials.gov identifier NCT07437586. ClinicalTrials.gov.
US Food and Drug Administration. 510(k) premarket notification K953853: Iamin Gel Wound Dressing, ProCyte Corp., decision date February 5, 1996. FDA.
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US Drug Enforcement Administration. Schedule III, 21 CFR 1308.13. eCFR.
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GHK-Cu