Why does GHK-Cu burn when injected?

This site found no published study measuring injection pain for GHK-Cu specifically. The documented, general contributors to injection site pain for injected solutions are the diluent's pH and preservative content, temperature, and how fast the solution is pushed in. Whether those explain the sting reported after GHK-Cu is inference from the broader injection literature, not a finding about GHK-Cu itself.

Educational use only. This database summarizes published research and is not medical advice. Where a dose appears it is a record of what a trial or clinic ran, or what people describe doing, with its source attached. Nothing here is a recommendation for personal use.

Part of injecting: sites, needles and safety. Subcutaneous vs intramuscular, where people inject, rotation and lipohypertrophy, needle gauge, aseptic technique, why it stings, and sharps disposal. Full walkthrough at /injecting.