Can B12 Shots Help With Weight Loss?

Vitamin B12 is an essential vitamin that your body needs to make new cells and tissue, including red blood cells. Your body can’t function properly without enough vitamin B12. And unlike some vitamins, your body can’t make it on its own. This means you have to get vitamin B12 from either food or supplements.

Vitamin B12 supplements are very popular, even though many people get enough from their diet. Many people believe vitamin B12 shots can help with a variety of health concerns, including weight loss. But are B12 shots really helpful for weight loss? Do they actually boost metabolism? And can they help your overall health? 

Before scheduling a B12 shot, here’s what you should know about what they can — and can’t — do. 

What are the benefits of B12 shots?

Vitamin B12 shots are a prescription supplement. They contain high (but safe) doses of vitamin B12. They can be beneficial — and even lifesaving — if you have low vitamin B12 levels.

Vitamin B12 helps your body make energy. When B12 levels are low, your body can’t make enough energy. This can impact your overall health and metabolism. B12 shots replenish your body’s B12 levels so you have more energy and don’t feel so run down.

If you have low vitamin B12 levels, B12 shots can deliver enough of the vitamin to:

• Protect your nerves, brain, and spinal cord

• Allow your bone marrow to make red blood cells

• Help your body create new cells (make DNA)

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But vitamin B12 shots don’t have proven health benefits unless you have a deficiency. If your B12 levels are already normal, your body will simply get rid of any excess — including the larger doses found in B12 shots.

Can B12 shots help with weight management?

There’s no good evidence that vitamin B12 shots can help with weight management. B12 shots don’t affect your metabolism if your B12 levels are already normal. B12 shots can’t help burn fat either.

Studies show that people who have a BMI over 30 or a larger body size can have low vitamin B12 levels. It’s possible that when people with larger body sizes start taking vitamin B12 supplements, they have better energy and are able to keep up with their activity goals. This may help them to be able to get to a weight that feels best. But there haven’t been any studies to show this direct relationship yet. 

It’s a good idea to have your vitamin B12 levels checked if you have a BMI over 30 or have a larger body size. If your levels are low, your healthcare team can offer recommendations about the best ways to get enough vitamin B12 to get your levels back up to normal.

Who’s at risk for having low vitamin B12 levels?

You’re more likely to have low vitamin B12 levels if you:

• Follow a vegan or vegetarian diet

• Have pernicious anemia

• Have Crohn’s disease, atrophic gastritis, or celiac disease

• Have a BMI over 30 

• Have had intestinal surgery or gastric bypass surgery

• Take medications for heartburn or GERD

• Are over 50 years old

• Are pregnant 

Ask your primary care provider about getting your vitamin B12 levels checked if you’re over 50 years old or at risk for low vitamin B12 levels. 

B12 shots vs. pills

People with a B12 deficiency can replace their B12 levels by taking supplements. B12 supplement options include:

• Pills

• Sublingual dissolving tablets

• Shots

• Nasal sprays

All of these options work to replace B12 levels. But some people find it easier to keep up with vitamin B12 supplements through shots. Unlike other forms of B12, vitamin B12 shots don’t need to be taken daily. Once your vitamin B12 levels return to normal, you only need one shot a month to keep your levels normal.

You can get B12 shots at most doctor’s offices and some retail pharmacies.

Does insurance cover B12 shots?

Insurance probably won’t cover B12 shots if you don’t have low B12 levels. If your B12 levels are normal but you still want to try a vitamin B12 supplement, oral or sublingual options may be a more cost-effective choice. 

Are B12 shots safe?

Vitamin B12 supplements are safe for most people. But it’s a good idea to check with your primary care provider before starting them — especially if you have any medical conditions or take prescription medications. 

Are there supplements that can help with weight management?

There’s no evidence that B12 shots help with weight management or boost your metabolism. There also isn’t any solid evidence that other vitamins or supplements can help with weight management. 

But here are some science-backed tips that can help you find a comfortable weight:

• Drink enough water. Your daily water needs depend on many things. But staying hydrated keeps your body working efficiently. 

• Avoid liquid calories. Calories from liquids like fruit drinks, soda, and sports drinks can lead to unintentional weight gain.

• Get more sleep. Most adults need 7-9 hours of sleep each night. Getting enough sleep is key to maintaining a comfortable weight. 

• Manage your stress levels. Stress can affect your weight and increase cravings for foods high in calories, fat, and sugar. 

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Written by:

Tracy Norfleet, MD, FACP

Dr. Tracy Norfleet is a board-certified Internal Medicine physician, health expert, and physician leader with over 20 years of experience practicing adult medicine. Dual-certified by the American Board of Obesity Medicine and the American Board of Lifestyle Medicine, Dr. Tracy possesses a wealth of knowledge and expertise in both traditional medical practices and innovative lifestyle interventions for chronic disease management and reversal.

Edited by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

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