Weight-Loss Supplements, Fat Burners, Detox Teas and Vinegar: Claim Check

Safety first

• The US FDA says many products that claim to help with weight loss, such as diet pills, fat-burning pills, and weight loss supplements, pills and teas, are likely to be contaminated with dangerous hidden ingredients. It adds that these products can lead to severe health issues and hospitalization, are sold online and in stores, and are not guaranteed to work. [1]
• If you or someone else has taken too much of a supplement or product and feels unwell, see Poisoning: what to do first. In the US you can call Poison Help at 1-800-222-1222; in an emergency call 911.
• If you take prescribed medicines, ask your pharmacist or clinician before adding any weight-loss product; see How interactions work.

Overview

This page checks claims for products sold for weight loss. It does not recommend any product. Evidence labels: established recommendation, promising but limited (some positive trials, but small, short or inconsistent), mixed, insufficient evidence and preclinical (lab or animal only; none is used here). Most evidence below is from short trials of 12 weeks or so in adults with overweight or obesity.

Claim check

Why safety deserves attention

• Hidden ingredients. The FDA says its list covers only a small fraction of contaminated products, and not being on the list does not mean a product is safe. [1] See Unsafe products and warnings and Product quality and contamination.
• Liver injury. A CDC-assisted investigation in 2013 found 40 people in 23 states with acute hepatitis of unknown cause after weight-loss or muscle-building supplements; of 25 people who reported taking one particular product, 17 of 22 with available data were hospitalized and one received a liver transplant. [8] NCCIH says liver injury is uncommon with green tea but has been reported, mainly with extracts in capsule or tablet form. [4] See Liver safety and supplements.
• Side effects and interactions. NCCIH lists nausea, constipation, abdominal discomfort and higher blood pressure as side effects of green tea extract, and says green tea can reduce blood levels of some medicines. [4]
• Pregnancy. NCCIH advises consulting a provider about caffeine if you are or might be pregnant. [4] Never take weight-loss medicines during pregnancy, per NIDDK. [9]
• Regulation. See How supplements are regulated and Reading supplement labels.

Better-supported options

Lifestyle programs, some prescription medicines and, for some people, surgery have stronger evidence than supplements; see Weight-loss medications and medical care, Healthy weight basics and Eating patterns compared.

Questions to ask before trying any product

• Has it been studied in people and published in a scientific journal? (NIDDK suggests asking this of weight-loss programs.) [10]
• What ingredients are in it, and could they interact with my medicines?
• Does it promise results like "lose 30 pounds in 30 days"? NIDDK lists such promises as warning signs. [10]

When to get help

Stop the product and seek medical care if you feel unwell after taking it; report side effects as described in Side effects, allergic reactions and reporting. Talk to a clinician before using weight-loss products if you take medicines, are pregnant, or have liver or heart conditions. If you feel driven to use laxatives, diuretics or pills to lose weight, see Weight and metabolism safety and Eating disorders and disordered eating.