GHK-Cu is a naturally occurring copper-binding tripeptide (glycyl-L-histidyl-L-lysine) found in human plasma, saliva, and urine. First discovered by Dr. Loren Pickart in 1973, plasma levels average 200 ng/mL at age 20 but decline to ~80 ng/mL by age 60. It has been extensively studied for wound healing, collagen synthesis, skin regeneration, and gene modulation, with decades of cosmetic use and a broad safety profile. Molecular weight is approximately 340 g/mol (as the copper complex), with the formula C14H24N6O4Cu.
Category: Skin & Tissue Repair. Evidence rating: F (anecdotal/unsupported).
Clinical status: Available in cosmetic formulations; no drug approval
GHK-Cu chelates copper(II) ions via its histidine residue and delivers bioavailable copper directly to cells, preventing free copper oxidative damage. It stimulates collagen, elastin, and glycosaminoglycan synthesis, modulates metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), attracts…
Research base: 3 registered clinical trials and 31 indexed publications reference GHK-Cu.
Safety considerations: Safety profile is excellent with minimal side effects reported in decades of cosmetic use and clinical research (PMID: 29986520); Topical forms are generally well-tolerated; mild skin irritation rare and typically limited to very sensitive skin; Injectable forms: mild injection site reactions, lightheadedness, nausea, flu-like symptoms possible; rotate injection sites to reduce local irritation.
Reviewed by the PeptideAtlas Editorial Team. Last reviewed: 2026-08-12.
Yes. GHK-Cu is widely available in serums and creams at typically 4% concentration. Topical application has the most human evidence and is effective for anti-aging — measurable collagen increases have been shown in skin biopsies from study participants. Apply 1-2 times daily to clean skin.
Injectable GHK-Cu provides higher bioavailability and deeper tissue penetration compared to topical. However, topical forms have the most evidence. According to researcher Dr. Pickart, a total treatment dosage of 100-200 mg of GHK injected intramuscularly may provide health benefits. Injectable should be administered under professional supervision.
Topical: 4% concentration applied 1-2 times daily. Injectable: 1-2 mg daily subcutaneous injection, 5 days on / 2 days off, for 8-12 weeks followed by assessment. Cycling is recommended: 30 days on, 30 days washout. Rotate injection sites (abdomen, thighs, upper arms).
Do not apply topical GHK-Cu at the same time as Vitamin C products, as copper counteracts Vitamin C's antioxidant properties. Separate application by several hours. GHK-Cu is not approved for any therapeutic use by the FDA.
GHK is the tripeptide alone (glycyl-histidyl-lysine). GHK-Cu is the copper complex form where copper(II) is pre-bound to the peptide. Both work through similar mechanisms, but GHK-Cu's pre-complexed copper may offer advantages in efficiency and stability for cellular delivery.