What Are Fat Burner Supplements?

Medically Reviewed by Melinda Ratini, MS, DO on February 29, 2024
3 min read

If you’ve been having a hard time losing weight, you may have considered taking a pill that has been advertised as a fat burner. Fat burners are a supplement that contains natural or artificial compounds. These supplements are supposed to help you slim down. 

Over-the-counter fat burners appeal to patients who want a way to magically treat obesity and believe that their benefits outweigh the risks. However, fat burner supplements may be neither safe nor effective. Read on to learn more. 

Fat burner supplements are said to work by increasing your resting metabolic rate. The active ingredients help get rid of body fat. However, research is still needed on the effects of ingredients like caffeine on your heart rate and blood pressure. 

The effectiveness of fat burner supplements is still in question. Though they’re commonly used for weight loss, there’s not a lot of evidence that they work. These supplements claim to block fat or carbohydrate absorption, curb your appetite, or speed up your metabolism. At the same time, some of these supplements can interfere with other medications you are on. 

Fat burners work by elevating your blood pressure and increasing your overall energy expenditure, which may eventually lead to weight loss over time. You should take precautions if you already have high blood pressure, though, because taking these supplements could lead to hypertension.

Studies have shown that fat burner supplements might not work the way you want them to. They don’t make your fat cells magically disappear. Instead, they can work by helping weight loss in other ways. This includes: 

  • Increasing your metabolism
  • Reducing the amount of fat your body absorbs
  • Suppressing your appetite  

Fat burners work in theory. However, it all depends on the ingredients. Since fat burner supplements aren’t FDA-approved, you can’t always be sure what’s inside. They can make any claim without factual evidence to support the claims. 

Fat burner supplements are typically tablets or "burn capsules" taken by mouth. They contain a range of vitamins, minerals, fiber, caffeine, herbs, and other plants. 

Caffeine. This is a common ingredient because it stimulates your nervous system and potentially helps burn calories. Supplements may contain more caffeine than your typical coffee, tea, or chocolate. 

Green tea extract. This is another common ingredient because green tea helps burn calories and reduce the fat you absorb from food.

Carnitine. This is a compound that boosts your metabolism and gives you energy. It can be found in meat and dairy products, and it’s made naturally by your liver and kidneys. However, its weight-loss benefits are questionable. 

Yohimbe. This is another plant compound that comes from the bark of an evergreen tree. It’s common in fat burner supplements but can cause negative effects. Yohimbe can cause: 

  • Headaches
  • Anxiety
  • Agitation
  • Increased blood pressure
  • Heart problems
  • Kidney failure

Soluble fiber. This ingredient isn’t found in all fat burners, but you can find some with high amounts of fiber. Fiber helps control your appetite, and soluble fiber can help prevent your body from absorbing fat from food. 

Most supplements contain a lot of different ingredients, typically more than what’s beneficial for your health. These unknown ingredients can cause fat burners to react unpredictably with your body. 

Fat burner supplements aren’t regulated by the FDA. Because of this, you may be taking a health risk by taking them.

 First, you don’t always get a complete picture of what is in the supplement. Some studies on these supplements have found ingredients inside that aren’t listed on the bottle.

Second, just because a supplement calls itself “natural” doesn’t mean that it’s safe. Some fat burner supplements have been linked to problems like liver damage. Some herbs, like ephedra, that were once used in fat burners are now banned by the FDA because they cause high blood pressure, mood change, irregular heart rate, stroke, seizures, and heart attacks.

 Before taking these supplements, you should talk to your doctor. Their ingredients may interfere with other medications you are taking. Fat burners can be dangerous and cause severe problems if mixed with the wrong drugs.

If you do want to try a fat burner supplement and have talked to your doctor, you can also check out websites run by the U.S. Office of Dietary Supplements to find the best supplements for you.