GHK Cu Peptide: What It Does for Body Composition and Metabolic Health 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 GHKCu Copper Peptide Therapy Skin & Healing Regeneration WO2019167070A1 Topical copper tripeptide composition and process of preparation. Google Patents Frontiers Exploring the beneficial effects of GHK Cu on an experimental model of colitis and the underlying mechanisms 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: