How Often Should You Get B12 Injections? A Realistic Schedule ELLEMES Medical Spa Gym goers spending monthly on vitamin B and C injections Have a f*cking word with yourself. Both are water soluble, so don't stick around for long in your system (12 14hrs) hence 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 Are Vitamin B12 Shots Right for You? B12 Injections For Weight Loss: How Often You Should Get Them How Long Does a B12 Shot Last?