A naturally occurring tripeptide-copper complex found in human plasma, saliva, and urine. One of the most studied peptides in dermatology for skin repair, anti-aging, and wound healing.
GHK-Cu (glycyl-L-histidyl-L-lysine copper complex) is a naturally occurring tripeptide that binds copper(II) with high affinity. It was first identified in human plasma by Dr. Loren Pickart in 1973, where it was found to stimulate liver cells to synthesize proteins at a rate similar to young tissue.
GHK-Cu is one of the few therapeutic peptides with substantial human clinical data supporting its topical use. It naturally declines with age — plasma levels drop from ~200 ng/mL at age 20 to ~80 ng/mL by age 60 — and this decline correlates with reduced wound healing capacity and skin aging.
GHK-Cu was first identified by Dr. Loren Pickart in the 1970s when he observed that liver tissue from young donors stimulated old liver cells to synthesize proteins at a rate comparable to young cells. The active factor was isolated and identified as the tripeptide glycyl-histidyl-lysine (GHK), which naturally forms a complex with copper(II) ions at physiological pH. The copper ion is essential for GHK-Cu's biological activity — the peptide and the metal ion are functionally inseparable.
GHK-Cu circulates naturally in human plasma at approximately 200 ng/mL in young adults, declining to about 80 ng/mL by age 60. This age-related decline correlates with reduced wound healing capacity, thinner skin, and decreased collagen synthesis — observations that have driven interest in GHK-Cu as an anti-aging compound.
In skincare, GHK-Cu is one of the most well-supported peptide actives. Multiple controlled clinical studies have demonstrated improvements in skin firmness, elasticity, fine lines, and overall skin thickness when applied topically. It is also used in post-procedure skincare (after laser treatments, chemical peels, and microneedling) to accelerate healing. For more on peptide skincare actives, see our skincare peptides guide.
At just 3 amino acids (Gly-His-Lys), GHK-Cu is the smallest therapeutically active peptide in this directory. Its copper-binding ability comes from the histidine imidazole ring (primary Cu²⁺ coordination) and the glycine amino group (secondary coordination). The lysine provides a positive charge that may aid cell membrane interaction.
GHK-Cu's mechanism is unique among therapeutic peptides because it operates through both gene regulation (the peptide component) and enzymatic cofactor delivery (the copper component). Genome-wide studies show GHK-Cu modulates the expression of over 4,000 genes, with a net effect of resetting gene expression patterns toward a younger, more regenerative state.
| Pathway | Effect | Significance |
|---|---|---|
| Collagen synthesis | Upregulates collagen type I, III, and V gene expression | Increases dermal thickness and mechanical strength |
| Lysyl oxidase activation | Cu²⁺ is an essential cofactor for LOX | Cross-links collagen and elastin fibers for structural integrity |
| Glycosaminoglycan synthesis | Stimulates decorin, heparan sulfate, and hyaluronic acid production | Improves skin hydration and extracellular matrix quality |
| Anti-inflammatory | Suppresses IL-6, TNF-α; blocks thromboxane formation | Reduces inflammation without immunosuppression |
| Antioxidant | Induces superoxide dismutase (SOD) and other antioxidant enzymes | Protects newly forming tissue from oxidative damage |
GHK-Cu has one of the stronger clinical evidence bases among therapeutic peptides, particularly for topical skin applications.
| Study Area | Design | Key Findings | Evidence |
|---|---|---|---|
| Facial skin remodeling | Double-blind RCT, n=67 women | Topical GHK-Cu cream improved skin density, thickness, and reduced wrinkles vs placebo after 12 weeks | Level I-II |
| Wound healing | Clinical studies, various wounds | Accelerated wound closure in surgical and chronic wounds; improved cosmetic outcome | Level II |
| Hair growth | Clinical pilot, alopecia | Increased hair follicle size and growth rate; comparable to minoxidil in some measures | Level II-III |
| Post-laser resurfacing | Clinical study | Faster healing and reduced erythema after fractional laser treatment | Level II |
| Gene expression | In vitro, genome-wide analysis | Modulated 4,000+ genes with net shift toward regenerative/anti-inflammatory profile | Preclinical |
Topical safety: GHK-Cu has an excellent topical safety profile with decades of use in skincare products. No significant adverse effects have been reported from topical application at standard concentrations (0.01-0.1%). Mild skin irritation may occur in sensitive individuals, particularly with higher concentrations.
Injection use: Some practitioners administer GHK-Cu via subcutaneous injection or mesotherapy for localized anti-aging effects. Safety data for injectable GHK-Cu is more limited than for topical use, though no serious adverse events have been reported in the available literature.
Copper toxicity: At the concentrations used in skincare and at typical injectable doses, copper toxicity is not a concern. The amount of copper delivered by GHK-Cu is orders of magnitude below toxic thresholds. Systemic copper supplementation should be monitored independently.
Wound healing interactions: GHK-Cu promotes wound healing and tissue remodeling, which is generally beneficial but means it should be used with caution on actively infected wounds where promoting tissue growth before clearing infection could be counterproductive.
| Jurisdiction | Status |
|---|---|
| FDA | Not approved as a drug. Used as a cosmetic ingredient (INCI: Copper Tripeptide-1). |
| Cosmetic industry | Widely used in premium skincare products (serums, creams, masks) |
| WADA | Not banned |