injectable vitamin b12 bodybuilding Injection: Energy Boost and Anemia Treatment — Mountainside Medical This product requires a valid prescription and is intended for veterinary use only. Vitamin B12 shots: Uses, benefits,
Description
I use the injectables from this great company
doi: 10.1016/j.atherosclerosis.2008.09.015

If switching the route of administration and dosage don't help, you may also have like a substrate issue

A few people notice temporary soreness at the injection site or mild flushing that fades quickly