Cashmere (Caffeine GHK Cu Tretinoin w Niacinamide) Strive Pharmacy SKINHI BLUE01 Copper Peptide GHK CU 1.4% All Over Body Care Size 50ml Aytz Chayim Aromatherapy 7 days on GHK Cu. Here's my honest update. I'm not going to hype this up because the real results don't even start until week 46. But something is already happening. 7 days on GHK Cu. Here's my honest update. I'm not going to hype this up because the real results don't even start until week 46. But something is already happening.