Vitamin B 12 intramuscular injections are also used therapeutically to help restore energy and combat various symptoms related to such deficiencies. Vitamin B 12 is essential to the development of healthy blood cells, nerve Benefits of Vitamin B12 Injections. Boosts energy and reduces fatigue Improves focus and mental clarity Supports metabolism and energy production Aids red blood cell and nerve health Veterinary Medicine 10% Butafosfan +Vitamin B12 Injection Recover Fatigue, Reduce Stress Response, Stimulate Appetite How Quickly Does a B12 Shot Work? Benefits & What to Expect