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.
Skin remodelling and the hair cycle
Tap each stage to see what happens.
Background: Skin & Hair Research
Skin and hair research looks at collagen synthesis, wound closure, pigmentation and the hair-follicle cycle.
Topical cosmetic research is often industry-funded and small. Injected use of cosmetic peptides has little human data.
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.
Higher tiers carry more weight. Filled tiers have evidence for GHK-Cu; tap to read it.
- Small controlled cosmetic studies have reported improvements in wrinkle appearance, skin density and elasticity with topical formulations.
2 cited sources.
- Narrative review1
- Randomised controlled trial1
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.
How to Read This Research
- Was the product topical or injected?
- Were results measured by instruments or by photos and self-assessment?
- Who funded the study?
- Cosmetic claims face a lower evidence bar than medical claims.
- Pigmentation-affecting compounds carry documented risks, including changes in moles.
- Anagen
- The active growth phase of a hair follicle.
- Dermis
- The skin layer beneath the surface that holds collagen.
- Melanocortin
- A hormone family that affects pigmentation and appetite.
Compare With Other Compounds
| GHK-Cu | Melanotan II | |
|---|---|---|
| Evidence grade | C — Early Human Research | E — Experimental / Limited Evidence |
| Regulatory status | Not FDA Approved | Not FDA Approved |
| Human data | Limited | Limited |
| Clinical trials | None identified | None identified |
| Research routes | Topical, Intradermal (cosmetic research) | Subcutaneous injection (unregulated use) |
| Cited sources | 2 | 2 |
Frequently Asked Questions
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
The KLOW and GLOW stacks are the most-discussed cosmetic peptide combinations. Here is what each ingredient actually has behind it.
Read the case study
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