Can You Have An Allergic Reaction to B Vitamins? Dr. Lam Experiencing itchy, red welts after your peptide injections? You're not alone, and the peptide itself usually isn't the problem. The real culprits? Histamine release, mast cell activation, gut imbalances, hormonal shifts, or Vitamin B12 injections Hempstead Therapy Centre Fun Fact Friday! Ever wondered Why is my B12 injection red? All B12s are cobalamins they have a cobalt atom at the center of a special ring shaped molecule called