GHK Cu vs NAD+: Which Longevity Peptide Should You Take or Stack? The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline Copper Peptide (GHK Cu) 2% Recovery Serum Two Weeks on GHK CU by Rory Uphold The Ladies Room Experiencing itching & burning from your GHK CU peptide injections? Try these to hacks: 1. Use a longer syringe to penetrate deeper into the fat cells. 2. Dilute the copper. Here I 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.