CJC 1295 Peptide: Benefits, Science, & Potential Uses. Peptide injections can sometimes cause redness or itching at the injection site, but most of the time this is not a true allergy. In the skin, we have mast cells that contain What causes a localized histamine reaction after a CJC (Growth Hormone Releasing Hormone) ipamorelin injection? That peptide reaction youre panicking about? , Red welts. Itching. Flushing., In most cases, this isnt an allergic reaction its mast cell activation., Your body was already inflamed, stressed, or Peptide Shots in St. Louis, MO The Saint Louis Med Spa