Amazon.com: Skin Perfection Copper Peptide Serum GHK CU 1% for Face & Hair Copper Peptides for Skin, Hair, & Scalp 1% Blue Liquid for Face, Neck, Body, Scalp Multi Use Serum Booster with GHK Cu Copper Peptide Serum with Hyaluronic Acid, Deep Hydrating Nourishing Facial Serum 30ML Gentle Anti Aging Skincare for All Skin Types, Firming & Smoothing for Men Women TikTok Shop By age 30, your skin produces about 25% less collagen. By 40, that number can reach 40%. This decline affects more than just how your skin looks. It changes how it heals, 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 GHK Cu Youthful Skin, Healthy Cells, Vibrant You.