feeling tired after vitamin b12 injection How soon do you feel less a injection? Why do I feel worse

Thankfully, several top-tier options are readily available through trusted sources

The drug has not been granted approval by Australia's Therapeutic Goods Administration, or any other health authority in the world, for human use and is therefore banned by the World Anti-Doping Agency

Metabolism 62 (4), 311322

Chemical substances shall not be used as a drug, medicine, active substance, medical aid, cosmetic product, a substance for production of a cosmetic product neither for human consumption that is any food or food supplement or otherwise similarly used on humans or animals

You can safely take vitamins B12 and D together