When you swallow a B12 pill, several steps have to work for it to be absorbed: stomach acid and the enzyme pepsin must release B12 from food or the supplement, the stomach must secrete a protein called intrinsic factor that binds to B12, and the B12-intrinsic factor complex must reach the ileum (the end of the small intestine) where it is finally absorbed
A: Many people notice improved energy within 24-48 hours of their first injection, though individual responses vary
Now, the FDA and other governing bodies better regulate vitamin shots to allow individuals to enjoy the benefits of B12 safely
Vitamin B12 Injections Vs Pills: Which Is Better
Unless instructed by a health care provider, this injected site is not recommended because untrained injectors may damage the sciatic nerve
Longer-Lasting Effects Depending on the dosage, the effects of Vitamin B12 injections can last anywhere from one week to a month, meaning fewer doses are needed to maintain adequate levels