If you've had a BAD experience with B12 shots, it's most likely that you do not tolerate or convert cyanocobalamin well (see if you can verify what form of B12 was in the shot that made you react poorly, and then stay away from that specific form if you can)
[6] In rat wound models, it produced concentration-dependent increases in connective tissue accumulation with collagen synthesis twice that of non-collagen proteins
Vitamin B12 shot side effects Most people tolerate vitamin B12 injections well, but possible side effects include: Mild: soreness or redness at injection site, mild diarrhea, nausea, headache, itching Rare but serious: allergic reactions (rash, swelling, difficulty breathing), low potassium (hypokalemia), dizziness or heart rate changes Get emergency medical help if you have signs of an allergic reaction to Vitamin B12: hives
It supports rapid recovery in tendons, muscles, nerves, and the digestive tracthelping your body bounce back from physical stress and inflammation