Effects of GHK Cu on MMP and TIMP Expression, Collagen and Elastin Production, and Facial Wrinkle Parameters The peptide world just got loud. Last week, RFK Jr. said roughly 14 peptides may come off the FDA's Category 2 restricted compounding pathway and move back toward legal pharmacy compounding. That Debunking the Myth That Mixing GHK Cu With Other Peptides Causes Damage Xcel Peptides GHK Cu is the compound your body made at 25 and quietly stopped making. Most people find it in overpriced serums. Few understand what it actually does, or what happens when you're not Diminishing Marginal Return Data Charts & Finance Templates Diminishing returns Wikipedia