Amazon.com: Skin Perfection Copper Peptide Serum GHK CU 1% for Face & Hair Copper Peptides for Skin, Hair, & Scalp 1% Blue Liquid for Face, Neck, Body, Scalp Multi Use Serum Booster with GHK Cu Peptide (50mg) Advanced Skin Rejuvenation & Healing Support Ghk Cu Intra Nasal Spray 50 mg 0.34 oz. Westend Medical Supply For subcutaneous injections, using shorter needles (4 5mm) is the safest choice to ensure medication stays in the fatty layer and avoids muscle injury. A 4mm needle is ideal, minimizing pain while keeping Product Question] Most effective way to deliver GHK Cu (Copper Tripeptide 1) through skin? : r SkincareAddiction Uses and Benefits #ghk GHK Cu is a naturally occurring peptide in human plasma that declines with age. When used in injections (usually subcutaneous), it can offer various benefits: Skin Rejuvenation and Anti Aging: