should b12 injections be kept in the fridge Methylcobalamin Injection (Vitamin B12) What happens if you inject

Last updated on Oct 16, 2025

Most patients who experience significant relief will notice it almost immediately

Heres the Reality Check While some people might report feeling a surge of energy within a day or two of receiving a B12 injection, its important to have realistic expectations

It includes 1-5 intramuscular or subcutaneous injections of 1000 mcg crystalline cyanocobalamin daily, followed by oral doses of 1000-2000 mcg/day Parenteral administration should be reserved for those with significant neurological symptoms NICE guideline: Vitamin B 12 deficiency in over 16s: diagnosis and management: Malabsorption as the confirmed or suspected cause of vitamin B 12 deficiency: Offer replacement to people if: lifelong intramuscular vitamin B12 Autoimmune gastritis is the cause They have had a total gastrectomy They have had a complete terminal ileal resection If the person has a vitamin B 12 deficiency because of malabsorption that is not caused by autoimmune gastritis, or a total gastrectomy or complete terminal ileal resection (for example, malabsorption caused by coeliac disease, partial gastrectomy or some forms of bariatric surgery): Offer vitamin B 12 replacement and Consider intramuscular instead of