Should I Take a Supplement on a GLP-1 or Dual GIP/GLP-1 Agonist?
Nutrients & SupplementsEveryday Health Special Report: Weight Loss Reframed

I’m on a Newer Weight Loss Drug. Should I Take a Supplement?

I’m on a Newer Weight Loss Drug. Should I Take a Supplement?
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Updated on April 29, 2026
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Newer weight loss drugs, such as semaglutide (Wegovy and Ozempic), tirzepatide (Zepbound and Mounjaro), and the recently FDA-approved orforglipron (Foundayo), are incredibly effective for weight loss. But the appetite suppression that comes with these medications may also increase the risk of nutrient deficiencies.

This raises the question of whether you should add a dietary supplement to your regimen if you’re on a newer weight loss drug. We talked with two registered dietitians to find out.

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Do You Need to Take a Supplement if You’re on a Weight Loss Drug?

It’s certainly possible, and your healthcare team can help you determine the answer based on your individual health. In general, though, anyone taking a GLP-1 should keep some key nutrition considerations in mind.

“These medications are well known to decrease the appetite, which itself causes people to take in fewer calories and possibly eat less balanced, nourishing foods,” says Beth Warren, a registered dietitian based in New York City.

Research suggests people who take GLP-1s decrease their calorie intake by 16 to 39 percent, and dipping below 1,200 calories per day for women or 1,800 calories per day for men can result in not getting enough vitamins and minerals.

One study found that more than 20 percent of adults who started a GLP-1 had nutrition deficiencies within one year.

Along with a loss of appetite, these drugs can cause diarrhea, nausea, and vomiting — factors that can certainly affect what and how much you’re eating.

“I’ve seen people eating less than 1,000 calories a day, because they felt too sick to eat. Others have no gastrointestinal issues,” says Jess DeGore, RDN, CDCES, owner of the virtual private practice Dietitian Jess in Pittsburgh. The calorie goal for adults ranges from 1,600 to 2,400 per day, depending on age and sex, according to the 2020–2025 Dietary Guidelines for Americans. “I worry about people who have a poor appetite and are not getting enough nutrients, whether they have a great quality of life when they can’t enjoy food and don’t feel great most of the time,” she says.

There is also a concern about dietary patterns. Relying on ultra-processed foods, which are typically lower in nutrition than whole or less-processed foods, can also increase your vulnerability to a nutrient deficiency if you don’t alter your eating habits to healthier patterns when on a GLP-1.

What’s more, if you’re losing weight rapidly, that’s another reason you should be on guard for potential nutrient deficiencies and make sure you have your bases covered, says DeGore.

What Supplements Do You Need if You’re Taking a GLP-1?

Your doctor may recommend you take fiber or other supplements in addition to steps such as: eating smaller, more frequent meals; limiting foods high in added sugar and saturated fats; and prioritizing protein.

“Supplement means ‘in addition to.’ These are meant to assist, not replace, nutrients in your diet,” says Warren.

The supplements your doctor or registered dietitian might recommend address common deficiencies, particularly those that may arise during weight loss. Talk to your healthcare practitioner for more guidance on exactly how much you need to take. If you’re worried about a deficiency, ask your provider about testing.

Vitamin B12

B12 is vital for blood and nerve cell health, and adequate intake prevents a form of anemia, which causes fatigue.

 “B12 is a common deficiency that we see in weight loss, so you want to make sure you’re getting enough every day,” says DeGore.

Vitamin D

DeGore says she recommends vitamin D, also known as the “sunshine vitamin,” to everyone, especially during the winter months, when there’s less sun exposure. Adequate vitamin D is important for strong bones and immune support, and a deficiency is commonly seen in people who are on a restrictive diet, she says.

 People who have obesity are also more likely to have a D deficiency than those at a healthy body weight. Taking a supplement may be helpful if your blood levels are lower than normal.

Fiber

Constipation is a common side effect of GLP-1 drugs. “Fiber is super important for folks on GLP-1s because these drugs can slow down digestion, often leading to constipation. Fiber helps keep things moving regularly,” says DeGore.

”While fiber supplements are available, I generally recommend whole-food sources; they offer a broader spectrum of nutrients and are less likely to cause side effects like belly bloating and gas,” DeGore adds. ”Instead, prioritize foods high in fiber, such as legumes, fruits, and vegetables. To avoid side effects, space these foods throughout the day, increase your intake gradually, and make sure to drink enough water.”

For some people, eating more fiber-rich foods may be difficult with a lower calorie intake. If meeting your daily fiber needs is challenging, taking a fiber supplement may be an option.

Probiotics

If you’re having gastrointestinal side effects due to the medication, probiotics may help repopulate your gut with good bacteria to ease symptoms, says DeGore. Ask your healthcare provider for their recommendations, but probiotics containing Bifidobacterium or Lactobacillus strains have been shown to improve stool frequency, which can be helpful if you’re struggling with constipation.

Multivitamin

A multivitamin won’t overcome poor dietary habits, but you can think of it as a security blanket, says Warren. Remember, though, that vitamins and minerals are more effectively absorbed through food than from a supplement, she adds.

EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Butsch WS et al. Nutritional Deficiencies and Muscle Loss in Adults With Type 2 Diabetes Using GLP-1 Receptor Agonists: A Retrospective Observational Study. Obesity Pillars. June 10, 2025.
  2. Mozaffarian D et al. Nutritional Priorities to Support GLP-1 Therapy for Obesity: A Joint Advisory From the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and the Obesity Society. Obesity Pillars. September 2025.
  3. Ismaiel A et al. Gastrointestinal adverse events associated with GLP-1 RA in non-diabetic patients with overweight or obesity: a systematic review and network meta-analysis. International Journal of Obesity. August 13, 2025.
  4. Vitamin B12 Fact Sheet for Consumers. National Institutes of Health Office of Dietary Supplements. December 15, 2023.
  5. Vitamin D Fact Sheet for Consumers. National Institutes of Health Office of Dietary Supplements. November 8, 2022.
  6. Johnson BVB et al. Dietary Supplement Considerations During Glucagon-Like Peptide-1 Receptor Agonist Treatment: A Narrative Review. Obesity Pillars. December 2025.
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Adam Gilden, MD, MSCE

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Diplomate of American Board of Obesity Medicine Foundation

Adam Gilden, MD, MSCE, is an associate director of the Obesity Medicine Fellowship at University of Colorado School of Medicine and associate director of the Colorado University Me...

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