What's the Difference Between NAD+ and B12 Shots and Which One Should You Choose? Greenwich Medical Spa 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 for Energy & Wellness Feeling worse after B12 Injection: Answering concerns. La Vie Med Spa McCartan's Boost Your Energy with ! Symptoms of low B12 includes: Constant fatigue Lack of energy Memory problems Pins and needles sensations Depression or mood