GHK Cu for Skin: SIGNAL's Guide to Rejuvenation 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 GHK Cu Peptide Progress: Week 3 Results Do you get injection site reactions from your GHK CU? , 3 tips to make it better, Room temp , Use a different injection site , Inject the medication sloowwwly , All in all even with injection