How Soon Do You Feel Less Tired After a B12 Injection? Still feeling tired even after good sleep? It might be more than just stress it could be Vitamin B12 deficiency. In Part 2, Dr. Pydi Satish, Consultant General Physician, explains the signs, causes, Feeling worse after B12 Injection: Answering concerns. La Vie Med Spa 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 How Can Vitamin B12 Shots Help Me Feel Refreshed Dr. Nasseri B12 Shots Woodland Hills EllEve Med Spa