GHK-Cu
GHK-Cu (copper tripeptide-1, glycyl-L-histidyl-L-lysine bound to copper) is a naturally occurring copper-binding tripeptide studied mainly as a topical cosmetic ingredient for skin firmness, collagen/GAG support, wound healing, and hair density. Human evidence comes largely from dermatology and cosmetic-product trials on skin; injectable/systemic use is far less studied and not an established practice.
GHK-Cu reconstitution calculator
Open full calculator →Typical dosing
| Goal | Range | Route | Frequency |
|---|---|---|---|
| Skin firmness / photoaging support | Topical 0.1-2% GHK-Cu cream or serum | Topical | Once or twice daily |
| Post-procedure / wound healing skin care | Topical GHK-Cu dressings or gels (varies by product) | Topical | Daily, per product instructions |
| Hair density / scalp support | Topical serum/solution formulations | Topical (scalp) | Daily |
| Systemic/injectable use | No standardized human dosing established — data are preclinical/anecdotal | Subcutaneous (not an established clinical practice) | Not applicable — insufficient evidence |
Ranges compiled from research literature — not a prescription.
How it works
GHK is a small copper-binding tripeptide (glycyl-L-histidyl-L-lysine) found naturally in human plasma, saliva, and urine. Circulating GHK levels are relatively high in young adults and decline substantially with age, which is part of why researchers led by Loren Pickart proposed it as a signal involved in tissue maintenance and repair. In its GHK-Cu form it binds copper with high affinity, and copper delivery/handling is central to several of its proposed activities, including copper-dependent enzymes involved in connective-tissue crosslinking.
In skin and wound models, GHK-Cu has been shown to stimulate synthesis of collagen, elastin, and glycosaminoglycans (GAGs) by dermal fibroblasts, and to modulate matrix metalloproteinases (MMPs) alongside their tissue inhibitors (TIMPs) in a way researchers describe as promoting more 'balanced' matrix remodeling rather than simple stimulation. Older rat wound-chamber studies from the Maquart group showed increased collagen and GAG/proteoglycan deposition with GHK-Cu treatment, and broader gene-expression analyses (Pickart & Margolina, 2018) found GHK-Cu associated with expression changes across genes linked to antioxidant response, DNA repair, and connective-tissue synthesis pathways.
Human evidence is concentrated in topical/cosmetic dermatology. Copper tripeptide-containing skin-care products have been tested in randomized and blinded trials, including alongside CO2 laser resurfacing, where GHK-Cu-containing regimens did not significantly outperform controls on objective erythema or wrinkle measures but were associated with higher patient-reported satisfaction. Separately, copper-peptide formulations have shown effects on hair follicle elongation and dermal papilla cell activity in vitro, and small studies report improved hair density versus baseline — but trials are small, short, and not comparable in size or rigor to established treatments like minoxidil.
What is honestly much less studied is systemic or injectable GHK-Cu. Most of the mechanistic and 'anti-aging'/regenerative claims beyond skin are extrapolated from animal, cell-culture, or gene-expression data rather than controlled human trials of injected GHK-Cu. Regulatory bodies have specifically distinguished topical from injectable use, treating the injectable route as a distinct, higher-uncertainty safety question.
Side effects & safety
- Topical GHK-Cu is generally well tolerated in published cosmetic trials, with mild irritation being the most commonly reported issue; it is widely sold as an over-the-counter cosmetic ingredient.
- Injectable/systemic GHK-Cu is far less studied in humans — dosing, pharmacokinetics, and long-term safety are not established, and it should not be assumed to carry the same safety profile as topical use.
- Because it is a copper-delivery compound, theoretical concerns exist around cumulative copper exposure with unsupervised or high-dose use, particularly by injection; individuals with copper-metabolism disorders (e.g., Wilson's disease) warrant particular caution.
- Product purity and sourcing vary widely across commercial GHK-Cu suppliers; unregulated research-grade or compounded material is not held to pharmaceutical manufacturing standards.
- It is not an FDA-approved drug for any indication — it is regulated/sold as a cosmetic ingredient, and injectable routes have drawn specific regulatory scrutiny for compounding safety.
- Given limited controlled human data outside topical skin use, consult a physician or dermatologist before use, especially for anything beyond an over-the-counter topical product.
Research
Primary sources — PubMed.
- Pickart L, Vasquez-Soltero JM, Margolina A. The Human Tripeptide GHK-Cu in Prevention of Oxidative Stress and Degenerative Conditions of Aging. Oxid Med Cell Longev. 2012. https://pmc.ncbi.nlm.nih.gov/articles/PMC3359723/
- 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. https://pmc.ncbi.nlm.nih.gov/articles/PMC6073405/
- Maquart FX, et al. In vivo stimulation of connective tissue accumulation by the tripeptide-copper complex GHK-Cu2+ in rat experimental wounds. J Clin Invest. 1993. https://pubmed.ncbi.nlm.nih.gov/8227353/
- Miller TR, et al. Effects of Topical Copper Tripeptide Complex on CO2 Laser-Resurfaced Skin. Arch Facial Plast Surg. 2006. https://pubmed.ncbi.nlm.nih.gov/16847171/
- Dou Y, et al. The potential of GHK as an anti-aging peptide. Aging Pathobiol Ther. 2020. https://pmc.ncbi.nlm.nih.gov/articles/PMC8789089/
- U.S. FDA. Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act. https://www.fda.gov/drugs/human-drug-compounding/bulk-drug-substances-used-compounding-under-section-503a-fdc-act