GHK Cu vs NAD+: Which Longevity Peptide Should You Take or Stack? 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 you're 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 Mitigating GHK Cu Injection Pain: Tips and Tricks Gabriel Alizaidy, MD, MS posted on the topic LinkedIn Why is the injection site painful after administering GHK Cu (Glycyl L Histidyl L Lysine Copper) 2mg mixed with normal saline?