Stop Injecting GHK Cu for Hair Loss (Doctor Explains Why) 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 GHK Cu Peptide Therapy Brea, CA Orange County GHK Cu (glycyl L histidyl L lysine copper) is a naturally occurring copper peptide in human plasma that declines with age. Known for its reparative and anti aging properties, it stimulates collagen synthesis, reduces inflammation, and improves skin health. 7% GHK CU ACCELERANT Platinum Skin Care Injectable GHK Cu: Beginner's Guide to Copper Peptide