Vitamin B-12 injections for weight loss: Do they work?

Date Updated: 08/26/2020

Answer Section

There's no solid evidence that vitamin B-12 injections aid weight loss.

Vitamin B-12 is a water-soluble B complex vitamin found naturally in a variety of foods, including meat, fish and dairy products. Vitamin B-12 is also added to some foods and is available as a dietary supplement. Vitamin B-12 injections are commonly prescribed to help prevent or treat pernicious anemia and B-12 deficiency.

Some weight-loss clinics offer vitamin B-12 injections as part of their weight-loss programs. Proponents of vitamin B-12 injections say the shots give you more energy and boost your metabolism, helping you shed unwanted pounds. But unless you have a vitamin B-12 deficiency, vitamin B-12 injections aren't likely to give you an energy boost.

Metformin (Fortamet, Glucophage, Riomet) is a drug sometimes used as part of a weight-loss strategy for people with type 2 diabetes. Vitamin B-12 deficiency can be a side effect of this drug. If you take metformin, talk to your doctor about strategies to maintain adequate B-12 levels.

Getting large amounts of vitamin B-12 through vitamin B-12 injections isn't likely to harm your health. But vitamin B-12 can interfere with the effectiveness of some medications, so if you receive vitamin B-12 injections, be sure to let your doctor know.

If you're hoping to lose weight, resist the lure of quick and easy solutions. What counts is a healthy lifestyle. Enjoy healthier foods in appropriate quantities and include physical activity in your daily routine.