b12 injections benefits side effects Shots — Why Are They So Popular? Feeling worse after B12 Injection:

Some patients, usually those with chronically low levels of B12, may notice results faster than this

for instance, an increase in energy or improvement in mood can often be felt in the first week or two, thanks to the vitamin B in the injection

A healthcare provider determines that a faster response is medically necessary

Panaccione R, Danese S, Sandborn WJ, et al

Alternative vitamin B12 supplementation is also a healthy, safe way to boost energy levels between vitamin B12 injections, when your doctor doesnt prescribe enough vitamin B12 to alleviate symptoms of chronic fatigue, brain fog, painful numbness and tingling, and memory problems