Benefits of Vitamin B12 Shots Complete Health Partners Do B12 shots actually work? Short answer YESfor the right people. Benefits may include: Increased energy Better focus Improved metabolism Especially helpful if you're deficient. If Benefits of B12 Injections for Optimal Health Vitamin B12 is essential for energy production, nervous system function, and red blood cell formation. However, oral B12 supplementation doesn't work well for everyoneabsorption can be limited by digestive issues, certain medications,