GHK-Cu
Also referenced as: Copper tripeptide-1, glycyl-L-histidyl-L-lysine copper
A naturally occurring copper-binding tripeptide with the strongest evidence in topical skin research.
- Evidence grade
- CEarly Human Research
Early Human Research
- Regulatory status
- Not FDA Approved
Used as a cosmetic ingredient in topical products, which is regulated differently from a drug. Cosmetic use does not imply approval for injection or therapeutic claims.
- Human data
- Limited
No registered clinical trials identified
- Last reviewed
- September 1, 2026
Overview
GHK is a tripeptide found in human plasma whose concentration declines with age. Bound to copper, it has been studied extensively in skin biology and appears in cosmetic formulations.
The gene-expression literature is genuinely interesting; the human clinical literature is small and focused on cosmetic outcomes such as wrinkle appearance and skin density.
Why It's Being Studied
- Collagen and extracellular matrix synthesis in skin.
- Wound healing and scar remodelling.
- Hair follicle biology.
- Broad gene-expression effects reported in cell studies.
Mechanism of Action
It carries copper into skin cells and appears to switch on the repair and collagen-building programmes those cells use.
GHK-Cu acts as a copper(II) chelator and delivery vehicle, influencing lysyl oxidase-dependent collagen crosslinking, matrix metalloproteinase balance and TIMP expression. Gene-expression profiling in fibroblasts has reported modulation of thousands of transcripts, including DNA repair and antioxidant pathways.
Research Areas & Routes Studied
- Skin ageing
- Wound healing
- Hair follicles
- Extracellular matrix
- Topical
- Intradermal (cosmetic research)
Evidence Summary
Small human studies exist for topical cosmetic endpoints, alongside a substantial in-vitro and gene-expression literature. Systemic use has no meaningful human evidence.
Human clinical evidence
- Small controlled cosmetic studies have reported improvements in wrinkle appearance, skin density and elasticity with topical formulations.
In-vitro studies
- Fibroblast gene-expression and collagen synthesis studies form the bulk of the mechanistic evidence.
Animal studies
- Wound healing models in rodents and pigs.
Reported Adverse Events in Research
- Topical use is generally well tolerated; irritation and contact sensitivity are possible.
- Injected or systemic use has no established safety profile, and copper accumulation is a theoretical concern.
Limitations of Current Evidence
- Human studies are small, often industry-run, and use cosmetic rather than clinical endpoints.
- Evidence for topical use should not be transferred to injection.
Documented Research Protocols
GHK-Cu — topical study protocols as reported
Summarise how topical GHK-Cu has been applied in published cosmetic and wound-healing studies.
View documented protocol
Why It Is Used
- Skin & Hair
Skin, Hair and Wound Healing
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Research References
- Narrative review
GHK peptide as a natural modulator of multiple cellular pathways in skin regeneration
Pickart L, Margolina A - Randomised controlled trial
Topical copper tripeptide in photoaged skin: controlled study