GHK-Cu, or glycyl-L-histidyl-L-lysine copper complex, is a naturally occurring copper peptide studied for collagen-related pathways, tissue remodeling, antioxidant defense, and skin repair [7] [8]
Sun M, Zhu C, Long J, Lu C, Pan X, Wu C
The mechanism itself is uncertain
Vorrius, B., Qiao, Z., Ge, J., & Chen, Q

Why 50mg is the standard vial size Common GHK-Cu vial sizes: 50mg (most popular) 100mg (economy size) 200mg (bulk) 10mg, 20mg (smaller, less common) Why 50mg is ideal: Perfect for 5-10 week protocol Lasts 25-50 doses (depending on dose used) Not too expensive (most 50mg vials $80-150) Easy reconstitution math Reasonable commitment (test if it works for you) Fits standard protocols Cost per dose from 50mg: If vial costs $100 Gives 25 doses at 2mg each = $4 per dose Very affordable for anti-aging Injectable vs topical GHK-Cu Injectable (most powerful): Systemic effects throughout body 80-90% bioavailability Works on skin from inside out Dose: 1-3mg, 3-7x weekly Best for comprehensive anti-aging Topical (easiest): Applied to skin surface Lower absorption (1-2% concentration in serum) Works locally on skin Daily application Best for focused skin improvement Can combine with injectable Which to choose: Injectable: Serious anti-aging, whole-body benefits Topical: Easier, good for skin-only goals Both: Maximum results See our copper peptides GHK-Cu guide , glow peptides guide , glow peptides , and injectable vs oral peptides
