GHK Cu Peptide Therapy: The Definitive Clinical Guide to Gene Modulation, Protocols, and Efficacy Is it necessary to cycle on and off of every peptide? The answer may not be as simple as you think, and it depends on *why* the peptide is being used. The GHK Cu Copper Peptide Shampoo Anti Hair Loss Promotes New Hair Growth eBay Amazon.com: GHK Cu Copper Peptide Supplement, Anti Aging & Hair Growth Support, Improves Skin Elasticity & Firmness, Thicker, Fuller Hair, Easy Absorption, Precisely Dosed, 90 Vegan Capsules : Health & Household