Is your goal to lose weight, get “cut,” meet body-composition standards, or just be healthier? Weight-loss supplements (sometimes marketed as “thermogenics,” “fat burners,” or “appetite suppressants”) might be a tempting solution, especially when you’re faced with obstacles—such as stress, injury, or lack of time—that make it hard to maintain your optimal weight. But before you take a supplement marketed for weight loss or fat loss, here are 3 things you should know.

#1 There’s little evidence that they work

Weight-loss supplements probably won’t help you meet your long-term goals. There just isn’t enough scientific evidence that weight-loss supplements alone can help you lose a significant amount of weight and keep it off. For example, some studies indicate that ingredients such as caffeine and green tea can increase energy expenditure and breakdown of fatty acid short term. However, there isn’t enough evidence that these effects translate into meaningful weight or fat loss in the long term. In addition, the following ingredients are all commonly touted for weight loss, yet the research to support these claims is either inconsistent or lacking.

Despite the marketing claims, more research is needed to determine which ingredients are safe and effective and in what amounts or combinations. Question the claims on the label, and remember: If it sounds too good to be true, it probably is.

#2 They often contain stimulants

Some ingredients in some weight-loss supplements might do more harm than good. For example, weight-loss and “thermogenic” supplements commonly contain stimulant ingredients, the most common being caffeine (from various sources). In general, taking too much or too many stimulants can put you at risk for side effects. Examples of other stimulants include:

Some weight-loss supplement ingredients are prohibited for use by Military Service Members, such as DMAA, DMBA, ephedra, and methylsynephrine. Some products have even been found to contain hidden drugs, other potentially harmful ingredients, or ingredients that haven’t been studied enough (or at all) in humans.

#3 They can’t replace diet and exercise

Weight-loss supplements aren’t “miracle pills” that will have you shedding pounds without any effort. Many weight-loss supplement labels and ads include statements about using them along with diet and exercise. In order to lose weight, you have to burn more calories than you consume. So, the key to losing weight and keeping it off is to follow a balanced eating plan and a structured exercise program—and sticking to it. When it comes to weight loss, it’s important to be patient (and realistic) because making meaningful changes to your body takes time. Visit the Fighting Weight Strategies portion of the Human Performance Resource Center (HPRC) website for tips to maintain a healthy weight—without using supplements.

For more information about weight-loss supplements:

Updated 21 February 2019


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U.S. Food & Drug Administration. (2019, 28 January 2019). Tainted Weight Loss Products.   Retrieved 21 February 2019 from