You may see ads for supplements that claim to help you lose weight. But many of these claims are not true. Some of these supplements can even have serious side effects.
Note for women: Pregnant or nursing women should never take diet medicines of any kind. This includes prescription, herbal, and other over-the-counter remedies. Over-the-counter refers to medicines, herbs, or supplements you can buy without a prescription.
Weight-loss Product Options
There are many over-the-counter diet products, including herbal remedies. Many of these products do not work. Some can even be dangerous. Before using an over-the-counter or herbal diet remedy, talk with your health care provider.
Nearly all over-the-counter supplements with claims of weight-loss properties contain some combination of these ingredients:
EPA-rich fish oil
There is no proof that these ingredients help with weight loss.
Safety of Over-the-Counter Products
Some ingredients in over-the-counter diet products may not be safe. The Food and Drug Administration (FDA) warns people not to use some of them. DO NOT use products that contain these ingredients:
Ephedrine is the main active ingredient of herbal ephedra, also known as ma huang. The FDA does not allow the sale of medicines that contain ephedrine or ephedra. Ephedra can cause serious side effects, including strokes and heart attacks.
BMPEA is a stimulant related to amphetamines. This chemical can lead to health problems such as dangerous high blood pressure, heart rhythm problems, memory loss, and mood problems. Supplements with the herb Acacia rigidula labeled on the packaging often contain BMPEA, even though this chemical has never been found in that herb.
DMBA and DMMA are stimulants that are chemically very similar to one another. They have been found in fat-burning and workout supplements. DMBA is also known as AMP citrate. Both chemicals can cause nervous system and heart problems.
Brazilian diet pills are also known as Emagrece Sim and Herbathin dietary supplements. The FDA has warned consumers not to buy these products. They contain stimulant drugs and drugs used to treat depression. These can cause severe mood swings.
Tiratricol is also known as triiodothyroacetic acid or TRIAC. These products contain a thyroid hormone, and they may increase the risk for thyroid disorders, heart attacks, and strokes.
Fiber supplements that contain guar gum have caused blockages in the intestines and esophagus, the tube that carries food from your mouth to your stomach and intestines.
Chitosan is a dietary fiber from shellfish. Some products that contain chitosan are Natrol, Chroma Slim, and Enforma. People who are allergic to shellfish should not take these supplements.
Manore MM. Dietary supplements for improving body composition and reducing body weight: where is the evidence? Int J Sport Nutr Exerc Metab. 2012;22:139-154. PMID: 22465867 www.ncbi.nlm.nih.gov/pubmed/22465867.
Strader DB, Navarro VJ, Seeff LB. Hepatotoxicity of herbal preparations. In: Boyer TD, Manns MP, Sanyal AJ, eds. Zakim & Boyer's Hepatology: A Textbook of Liver Disease. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 26.
U.S. Food and Drug Administration. Beware of products promising miracle weight loss. Last updated 2/11/2015. Available at: www.fda.gov/forconsumers/consumerupdates/ucm246742.htm. Accessed on May 6, 2015.
Laura J. Martin, MD, MPH, ABIM Board Certified in internal medicine and hospice and palliative medicine, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.