Over-the-counter weight-loss pills
The temptation to use over-the-counter weight-loss pills to lose weight fast is strong. But are these products safe and effective?
By Mayo Clinic Staff
The appeal of losing weight quickly is hard to resist. But do weight-loss pills and products lighten anything but your wallet? And are they a safe option for weight loss? Here's a look at some over-the-counter weight-loss pills and what they will and won't do for you.
Setting realistic expectations
There's no magic bullet for losing weight. The most effective way to lose weight and keep it off is through lifestyle changes. Eat a healthy low-calorie diet with lots of fruits and vegetables and be physically active.
Weight-loss pills — prescription medicines, nonprescription drugs, herbal medicines or other dietary supplements — are all, at best, tools that may help with weight loss. But there is relatively little research about these products, and the best studied of these are prescription weight-loss drugs.
For example, a 2014 study reviewed 21 long-term trials of prescription drugs for treating obesity. The researchers concluded that when a person makes appropriate lifestyle changes, a prescription weight-loss drug increases the likelihood of achieving "clinically meaningful" weight loss within a year.
Clinically meaningful weight loss — enough weight loss to begin lowering the risk of cardiovascular disease, diabetes and other diseases — is generally defined as 5 percent or more of body weight.
It's important to consider, however, that weight loss achieved in a research setting may be greater than in actual practice. Also, possible side effects and adverse reactions to weight-loss pills can affect the treatment outcome.
A reasonable expectation, therefore, is that prescription weight-loss pills may be beneficial, but they won't be magical. They do not work for everyone, and their benefit may be modest. And researchers know much less about the potential benefits and risks of over-the-counter weight-loss products.
Understanding over-the-counter treatment regulations
Over-the-counter weight-loss treatments fall into two general categories:
- Nonprescription drugs
- Dietary supplements
The standards for regulating the production and marketing of these two types of treatments are different. For a nonprescription drug, such as orlistat (Alli), the drug company must provide the Food and Drug Administration (FDA) with results from human (clinical) trials that show the safety and effectiveness of the drug at the nonprescription dose.
The maker of a dietary supplement is responsible for ensuring the safety of a product and making honest claims about possible benefits. However, the maker's claims are not subject to FDA review or approval before marketing. Also, the type or quality of research used to support claims can vary.
If the FDA can demonstrate that a substance is unsafe, the agency can ban the product or ask a manufacturer to withdraw it voluntarily. The FDA may also take action against a manufacturer if there is no evidence at all to support a claim.
These differences in research, production and marketing can make it difficult for people to make informed decisions about products.
Interpreting claims on weight-loss supplements
When a dietary supplement is marketed as "clinically proven" to cause weight loss, there should be some type of clinical evidence to support it. Such a claim, however, provides no details about the clinical research.
For example, raspberry ketone supplements are marketed as clinically proven, natural weight-loss products. As of November 2014, the results of only one clinical trial with raspberry ketone had been published. The results include the following information:
- The eight-week trial used a multi-ingredient supplement with raspberry ketone, caffeine, bitter orange, ginger root extract and garlic root extract, as well as other herbs, vitamins and minerals.
- Seventy obese adults were randomly assigned to receive either the supplement or an inactive ingredient (placebo).
- All of the participants were placed on a restricted diet and exercise program.
- Forty-five people completed all eight weeks of the trial.
- Among people completing the trial, the average weight loss in the supplement group was 4.2 pounds (1.9 kilograms).
- The average weight loss in the placebo group was 0.9 pounds (0.4 kilograms).
While the difference between the two groups was significant, the weight loss in the treatment group was still modest. And the trial was only eight weeks, which is not long enough to know if the supplement will help promote weight loss over the long term. Because the supplement included multiple ingredients, it's not possible to judge which ingredients caused a treatment effect.
Therefore, the size, method and duration of the trial provide insufficient evidence to draw conclusions about the potential benefits of raspberry ketone.
Dec. 19, 2014
See more In-depth
- Dietary supplements for weight loss. National Institutes of Health Office of Dietary Supplements. http://ods.od.nih.gov/factsheets/WeightLoss-HealthProfessional/. Accessed Nov. 13, 2014.
- Hensrud DD (expert opinion). Mayo Clinic, Rochester, Minn. Nov. 28, 2014.
- Yanovski SZ, et al. Long-term drug treatment for obesity: A systematic and clinical review. JAMA. 2014;311:74.
- Lopez HL, et al. Eight weeks of supplementation with a multi-ingredient weight loss product enhances body composition, reduces hip and waist girth, and increases energy levels in overweight men and women. Journal of the International Society of Sports Nutrition. 2013;10:22.
- Bitter orange. Natural Medicines Comprehensive Database. http://www.naturaldatabase.com. Accessed Nov. 23, 2014.
- Alli. GlaxoSmithKline Consumer Healthcare, L.P. http://www.accessdata.fda.gov/drugsatfda_docs/label/2014/021887Orig1s006lbl.pdf. Accessed Nov. 26, 2014.
- Bitter orange. National Center for Complementary and Alternative Medicine. http://nccam.nih.gov/sites/nccam.nih.gov/files/Herbs_At_A_Glance_Bitter_Orange_06-13-2012_1.pdf. Accessed Nov. 26, 2014.
- Chitosan. Natural Medicines Comprehensive Database. http://www.naturaldatabase.com. Accessed Nov. 23, 2014.
- Chromium. Natural Medicines Comprehensive Database. http://www.naturaldatabase.com. Accessed Nov. 23, 2014.
- Conjugated linoleic acid. Natural Medicines Comprehensive Database. http://www.naturaldatabase.com. Accessed Nov. 23, 2014.
- Onakpoya I, et al. The use of green coffee extract as a weight loss supplement: A systematic review and meta-analysis of randomised clinical trials. Gastroenterology Research and Practice. 2011:382852.
- Green coffee extract. Natural Medicines Comprehensive Database. http://www.naturaldatabase.com. Accessed Nov. 23, 2014.
- Green tea extract. Natural Medicines Comprehensive Database. http://www.naturaldatabase.com. Accessed Nov. 23, 2014.
- Guar gum. Natural Medicines Comprehensive Database. http://www.naturaldatabase.com. Accessed Nov. 23, 2014.
- Hoodia. Natural Medicines Comprehensive Database. http://www.naturaldatabase.com. Accessed Nov. 23, 2014.