GHK Cu for Skin Rejuvenation WeCare Pharmacy Wellness peptide craze: why people are injecting drugs 'not for human consumption' GHK Cu is more than a skincare trend its a copper peptide involved in repair, regeneration, and cellular signaling., This peptide has been studied for its connection to collagen production, skin If your GHK injection site gets irritated try this , 1. Dilute it by adding more water to the syringe , 2. Let it sit until it reaches room temperature , Also, make sure youre rotating injection