GHK-Cu (Glycyl-histidyl-lysine copper)
GHK-Cu is a small peptide of three amino acids bound to copper; its blood level drops noticeably with age. It is studied for skin renewal, collagen production, wrinkle reduction, and wound healing.
Gly-His-Lys + Cu²⁺ chelate via the His imidazole and the N-terminal amino group of Gly. ~341 Da (peptide). Discovered in 1973 by Loren Pickart.
The leading cosmetic and regenerative peptide. Plasma level: 200 ng/mL (age 20) → 80 ng/mL (age 60). Regulates the expression of 4,000+ genes (31.2% of the genome). Clinical data: ↑collagen I/III, ↓wrinkles by 55.8% (volume) and 32.8% (depth). Wound healing.
Signaling peptide → activates TGF-β + fibronectin receptors of fibroblasts → ↑COL1A1/COL3A1, ↑elastin, ↑GAG. Cu²⁺ → cofactor of lysyl oxidase (collagen cross-linking) + SOD (antioxidant) + tyrosinase. ↑VEGF, ↑NGF → angiogenesis + neurogenesis.
Studies used 1–2 mg SC systemically 2–3 times a week; topically, a 2–5% serum (cosmetics) or a 1–3 ppm cream.
Level C-D Animal studies. Effects have been shown in animals. Whether they carry over to humans has not been proven.
No human RCTs have been conducted. Cosmetic tests ≠ pharmaceutical RCTs. Systemic use is an extrapolation from topical data.
Research peptides are laboratory reagents (Research Use Only). They are not medicines and are not intended for use in humans or animals.