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 Injections for Energy: Benefits and How It Works AZ IV Medics B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics B12 Injection Frequency: How Often Should You Get a B12 Shot? Liv Hospital