B12 Injections for Weight Loss: Evidence and NHS Guidance Bolt Pharmacy Main benefits of B12 injections 1) Increased energy & reduced fatigue B12 helps convert food into usable energy Deficiency often causes tiredness, weakness, and low stamina 2) Healthy red blood cells Prevents B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics CYANOCOBALAMIN INJECTION, USP 10,000mcg 10mL (1,000mcg mL) 10mL VIAL