Why does GHK-Cu burn when injected?

This site found no published study that measured shot pain for GHK-Cu. For injected liquids in general, the known causes of pain are how acidic the mixing liquid is, its preservative, its temperature, and how fast it is pushed in. Whether those explain the sting people report after GHK-Cu is a guess from the wider research on shots, not a finding about GHK-Cu itself.

Full injecting guide: sites, needles, rotation, safety

Copper peptides for skin and hair: what real people saw

Copper peptides for skin and hair: what real people saw

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, site rotation, lipohypertrophy, needle length and gauge, vial hygiene at injection time, travel syringes, scar tissue, and when to stop and see a clinician. Full walkthrough at /injecting.