Cyanocobalamin: The REAL Reason Why You Should Avoid Synthetic B12 B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics B12 Injections: Who Should Get Them and How Long Do They Last? 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,