GHK-Cu: Complete Guide

GHK-Cu consists of three amino acids — glycine, histidine, and lysine — complexed with a copper(II) ion. It was discovered in the 1970s when Dr. Loren Pickart observed that albumin from young blood (age 20-25) could stimulate old liver tissue to produce proteins characteristic of younger tissue. The active factor was isolated and identified as GHK, which naturally binds copper with high affinity.

In human plasma, GHK-Cu concentrations are approximately 200 ng/mL at age 20, declining to roughly 80 ng/mL by age 60. This age-related decline has led researchers to hypothesize that falling GHK-Cu levels contribute to the reduced tissue repair capacity associated with aging.

GHK-Cu's significance extends beyond simple copper delivery. Gene expression studies using the Broad Institute's Connectivity Map (CMAP) revealed that GHK-Cu affects the activity of 4,047 human genes — roughly 6% of the human genome. The pattern of gene modulation favors tissue repair: upregulating genes involved in collagen synthesis, stem cell differentiation, anti-oxidant defense, and angiogenesis while suppressing genes involved in inflammation, fibrin formation, and tissue destruction.

GHK-Cu operates through several distinct but interconnected pathways:

• Copper delivery and metalloenzyme activation: Copper is a cofactor for enzymes critical to tissue repair including lysyl oxidase (collagen and elastin cross-linking), superoxide dismutase (SOD, antioxidant defense), and cytochrome c oxidase (cellular energy production). GHK-Cu delivers bioavailable copper to tissues where these enzymes function.
• Collagen synthesis stimulation: GHK-Cu upregulates the expression of collagens I, III, and V — the primary structural proteins of skin, tendons, and blood vessels. It simultaneously increases decorin expression, a proteoglycan that regulates collagen fibril assembly, resulting in more organized collagen architecture.
• Glycosaminoglycan synthesis: GHK-Cu stimulates production of hyaluronic acid, dermatan sulfate, and chondroitin sulfate — components of the extracellular matrix that provide tissue hydration and structural support.
• Anti-inflammatory signaling: GHK-Cu suppresses the expression of pro-inflammatory cytokines including TNF-α, IL-6, and TGF-β while reducing oxidative damage markers. It also inhibits thromboxane formation and limits neutrophil infiltration into damaged tissue.
• Stem cell recruitment: Research suggests GHK-Cu attracts mesenchymal stem cells and macrophages to wound sites, and promotes the transition from inflammatory M1 macrophages to reparative M2 macrophages.

Skin Rejuvenation and Anti-Aging

This is the most commercially developed application for GHK-Cu. Clinical studies have demonstrated that topical GHK-Cu:

• Increased collagen production in photoaged skin by 70% in a 12-week study
• Reduced fine lines and wrinkles more effectively than retinol and vitamin C in controlled comparisons
• Improved skin elasticity, firmness, and thickness as measured by ultrasound
• Enhanced skin clarity and reduced hyperpigmentation

GHK-Cu is a common ingredient in high-end skincare products (often listed as "copper peptide" or "copper tripeptide-1") and is considered one of the most evidence-supported active ingredients in cosmetic dermatology.

Wound Healing

GHK-Cu accelerates wound healing through multiple mechanisms: increasing collagen deposition, stimulating angiogenesis (new blood vessel formation), attracting immune cells, and promoting epithelial cell migration. Animal studies show faster wound closure, higher tensile strength, and better cosmetic outcomes in GHK-Cu-treated wounds compared to controls.

Hair Growth

Research on GHK-Cu and hair growth has shown promising results. The peptide appears to increase hair follicle size, stimulate hair growth, and prolong the anagen (growth) phase of the hair cycle. Studies have demonstrated effects comparable to minoxidil in some models. GHK-Cu also increases follicular blood supply through angiogenesis. See the peptides for hair growth guide for more context.

Lung and Tissue Fibrosis

Gene expression studies suggest GHK-Cu has anti-fibrotic potential, downregulating genes associated with excessive scarring and fibrosis. This has generated interest in its potential for conditions such as pulmonary fibrosis and liver fibrosis, though clinical trials for these indications have not been conducted.

GHK-Cu dosing varies significantly by route and application:

Route	Typical Dose	Application
Topical (cream/serum)	1–3% concentration	Skin anti-aging, wound healing
Subcutaneous	200–500 mcg daily	Systemic anti-aging, tissue repair
Microneedling	Applied after treatment	Enhanced skin penetration
Intradermal (mesotherapy)	50–200 mcg per session	Targeted skin rejuvenation, hair restoration

For injectable GHK-Cu, standard reconstitution with bacteriostatic water applies. Use the peptide calculator for volumes. See the reconstitution guide for preparation instructions.

For detailed protocols, visit the GHK-Cu dosage guide.

As a naturally occurring human peptide, GHK-Cu has an excellent safety profile:

• Topical use: Generally well-tolerated. Occasional mild irritation or redness, particularly with high concentrations or in combination with other active ingredients (e.g., acids, retinoids)
• Injectable use: Injection site reactions (redness, mild swelling) are the primary reported effect
• Copper sensitivity: Individuals with Wilson's disease or copper metabolism disorders should avoid GHK-Cu due to its copper content
• No systemic toxicity: Studies have not shown evidence of systemic toxicity at research doses
• Drug interactions: GHK-Cu should not be used simultaneously with strong oxidizing agents (such as high-concentration benzoyl peroxide or vitamin C at pH <3) as they can destabilize the copper complex

One consideration specific to GHK-Cu is its blue-green color (from the copper ion), which can temporarily tint skin when applied topically at high concentrations. This is cosmetic and resolves as the product absorbs. More details in the GHK-Cu side effects guide.

GHK-Cu is somewhat unique among research peptides in that it has significant evidence supporting both topical and injectable routes:

Factor	Topical	Injectable (SC)
Primary use	Skin anti-aging, surface wounds	Systemic tissue repair, hair growth
Penetration	Epidermis and upper dermis	Systemic distribution
Evidence level	Multiple clinical studies, commercial use	Primarily preclinical and research use
Convenience	Daily application, no preparation	Requires reconstitution and injection
Typical duration	Ongoing (as skincare)	Cycles of 4–8 weeks

For purely cosmetic skin aging concerns, topical GHK-Cu products represent the most accessible and evidence-supported approach. Injectable use is more common in research settings targeting systemic effects, deep tissue repair, or hair follicle stimulation.