Amazon.com: Neurogan GHK Cu Copper Peptide Hair & Scalp Serum 2400mg, 4% Copper Peptides Fast Absorbing, Water Based Formula for Hair Softness & Shine Cosmetic Dry Scalp Moisturizer Spray, Made in USA : Mitigating GHK Cu Injection Pain: Tips and Tricks Gabriel Alizaidy, MD, MS posted on the topic LinkedIn In Vitro and in Vivo Studies of pH Sensitive GHK Cu Incorporated Polyaspartic and Polyacrylic Acid Superabsorbent Polymer ACS Omega 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