GHK Cu vs NAD+: Which Longevity Peptide Should You Take or Stack? GHK Cu 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 standard logic for cyclingusing something Full honest & unfiltered experience with GHK Cu 1 month after completing a 12 week cycle: Weeks 12: No noticeable changes. Weeks 34: Skin rash (rib area) worsened. Weeks 56: Extreme dryness, flaking, Frontiers Exploring the beneficial effects of GHK Cu on an experimental model of colitis and the underlying mechanisms Copper Peptide GHK Cu Copper Peptide