Stella (GHK Cu Estriol Niacinamide Tretinoin) BloomMD Alternating tretinoin and GHK Cu (copper peptides) nightly maximizes anti aging benefits while minimizing irritation. , Both are potent but DIFFERENT actives. Tretinoin speeds up cell turnover and 12 weeks in, and my skin has NEVER looked better! GHK peptides are doing their thing. Alright, I need to give you an updateit's been 12 weeks since I started using GHK GHK CU Before and After Pictures Topical GHK Cu Skin Results, Face Serum Reviews & Photo Results Neurogan Health 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