What is the dosage for ghk cu injection? Injectable GHK Cu: Beginner's Guide to Copper Peptide Have you used peptides? What are your thoughts? Let me know below Peptides are short chains of amino acids that play vital roles in cellular signaling and repair throughout the body. PDGF injections are trending fast online, but many patients are not being told the full story including that most PDGF products were never FDA approved for injection into the face. We're now seeing Subcutaneous Injection: What It Is and How to Give One