The GHK Cu pen works. But needles at home were never the answer. We took the same clinically backed copper peptide complex and put it into a serum you can use in 30 seconds, Glow Peptide Protocol GHK Cu, BPC 157, TB 500 Neurogan Health 7.4 Subcutaneous Injections Clinical Procedures for Safer Patient Care 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