Redness after a peptide injection can feel alarming but in most cases, its completely normal. , If youve noticed a pink or red halo at the injection site especially with peptides like GHK Cu In Vitro and in Vivo Studies of pH Sensitive GHK Cu Incorporated Polyaspartic and Polyacrylic Acid Superabsorbent Polymer ACS Omega My skin spot on GHK Cu : r Biohackers 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