Do Weight Loss Supplements Work?

Learn whether weight loss supplements actually work, and learn other ways you can maximize fat loss with diet.

Ben Greenfield
6-minute read
Episode #18

From green tea to bitter orange, and from hoodia to heartleaf, herbal formulations and over-the-counter weight loss supplements are constantly being featured in advertisements online, on TV,  and on the radio, and also at your local gym, grocery store, and pharmacy. So do these calorie-burning cocktails actually work, or are they a waste of your money? In this article, you’ll find out what the research has to say about weight loss supplements and fat burning pills, and you’ll also learn how to maximize fat loss by choosing the right food.

What Are Weight Loss Supplements?

As you’ll learn later in this article, some foods can be considered weight loss supplements. But for the purpose of this discussion, a weight loss supplement is any pill, capsule, or tablet that includes herbal or chemical ingredients formulated specifically for the purpose of increasing your metabolism (allowing you to burn more calories) or decreasing your appetite (helping you take in fewer calories). In scientific literature, weight loss supplements are commonly referred to as thermogenic aids.

The poor performance of weight loss supplements when they aren’t paired with exercise, combined with the fact that I am the Get-Fit Guy and am supposed to be teaching you how to effectively enhance exercise, dictates that the remainder of this article will focus on giving you instructions for properly using weight loss supplements for workouts, and not for lounging on the couch while feasting on fat loss pills.

Do Weight Loss Supplements Work?

There have been many studies performed on weight loss supplements, although most of them were funded by the weight loss supplement industry. But the basic premise of these studies is fairly consistent: give a group of people a weight loss supplement, then measure the change in resting energy expenditure, or calories burned while sitting or lying down. The good studies go a step further and also measure the change in exercise energy expenditure, or calories burned during physical activity.

An Important Weight Loss Supplement Study

One of the most recent and comprehensive weight loss supplement studies to date was titled “Acute Effects of a Thermogenic Nutritional Supplement on Energy Expenditure and Cardiovascular Function at Rest, During Low-Intensity Exercise, and Recovery from Exercise.” In this study, researchers examined the effect of a weight loss supplement containing some of the most popular ingredients you’ll find in most weight loss supplements today:

  • caffeine,

  • capsaicin (a component of hot peppers),

  • bioperine (an extract of black pepper), and

  • big doses of niacin (vitamin B12).

The researchers gave men and women of average fitness this weight loss supplement and then measured their metabolism, blood pressure, heart rate, and their carbohydrate and fat burning for 50 minutes. They then measured all of these same variables during an hour of treadmill walking, and then measured them again during 50 minutes of post-exercise recovery.

Compared to a group that only took a placebo, the weight loss supplement group experienced a resting energy expenditure that was 6% higher, and a post-exercise energy expenditure that was 4-8% higher. Their maximum oxygen consumption during the exercise protocol was slightly higher, with a small but significant increase in lipid metabolism (fat burning) during exercise. But that’s not all--heart rate and blood pressure were also significantly higher during and after exercise in the weight loss supplement group.


All content here is for informational purposes only. This content does not replace the professional judgment of your own health provider. Please consult a licensed health professional for all individual questions and issues.

About the Author

Ben Greenfield

Ben Greenfield received bachelor’s and master’s degrees from University of Idaho in sports science and exercise physiology; personal training and strength and conditioning certifications from the National Strength and Conditioning Association (NSCA); a sports nutrition certification from the International Society of Sports Nutrition (ISSN), an advanced bicycle fitting certification from Serotta. He has over 11 years’ experience in coaching professional, collegiate, and recreational athletes from all sports, and as helped hundreds of clients achieve weight loss and fitness success.