Vitamin B12 is an essential vitamin, and low levels are linked to obesity. B12 shots could improve fatigue if you have a deficiency, but there’s not much research on them as a weight loss treatment.

This article was reviewed by Lynn Marie Morski, MD, JD. There’s not much research on B12 shots for weight loss. People with obesity tend to have lower vitamin B12 levels, but it’s unclear if B12 shots ...