GHK Cu DrBrainRX Should Bodybuilders Take GHK Cu? Neurogan Health Many people are being told to inject peptides like BPC 157, GHK Cu, or TB500 right over the area of pain, thinking it will deliver the peptide directly into the injured tissue. Thats simply not true. 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