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Do Fat-Burning Pills Work? We Ask the Experts

We talk to experts about what is true—and what's false—about the mystique of fat-burning pills.

We all know that the best way to encourage sustainable weight loss is with a lifestyle change: Eat healthy, get more exercise, and drink more water. But sometimes, we need a little bit of help, and for some, that means turning to diet pills, otherwise known as fat-burning pills. About 15 percent of American adults have used a weight-loss supplement in their lives, and every year, we spend about $2.1 billion on them.

"Making lifestyle changes, such as following a healthy eating pattern, reducing calorie intake, and engaging in physical activity, is the foundation for achieving successful, long-term weight loss," explains Maggy Doherty, Registered Dietitian at Balance One Supplements. "Unfortunately, since making dietary and lifestyle changes can be quite difficult, many people turn towards dietary supplements, like fat-burning pills, in hopes that this will help them achieve their weight loss faster and easier."

Over the years, diet pills have evolved from dangerous amphetamines and laxatives to a host of natural and synthetic options on the market today. But are today's options effective–or even safe? Our experts help us get to the bottom of it.

Do fat-burning pills actually work?

The question of whether weight loss pills work or not depends on what results you're hoping for.

"Any recommendations really come after finding out exactly what someone wants to get out of them," explains Brad Dunlap, Operations Manager of Supplement Warehouse. "Are they looking for something to make them sweat? Stave off hunger? But one thing's for sure: Any supplement you use is only a support within a greater framework for weight loss."

"If the question is, 'Will a diet pill work without change in my diet or activity level?' then the answer is a resounding 'no,'" explains Paul Claybrook, MBA, MS, CN, Certified Nutritionist at

"Fat burners are designed to support weight loss, which means that they're not a magic 'fix' for your weight loss goals," adds Nate Masterson, health expert and the head of natural product development at Maple Holistics. "This means that they can be used alongside a healthy diet and exercise plan to assist fat-burning."

This is the case of a few options on the marketplace today, like those below. Bear in mind that any time you add any supplement to your regular routine, you should check with your healthcare provider first–especially if you have a medical condition like diabetes or high blood pressure.

Dr. Lori Shemek, PhD, CNC, author of Fire-Up Your Fat Burn!, warns that the side effects of some products can range from unpleasant to deadly.

"Fat burners do not need to be regulated by the FDA, which poses inherent risk," Shemek says. "There have been instances where the fat-burners have been removed from shelves due to high blood pressure, strokes, seizures, and even death."

Caffeine pills

Caffeine pills are one of the most popular weight loss supplements, having "the ability to curb appetite and increase energy levels, thus facilitating the ultimate goal of weight loss," notes Masterson.

But Masterson also notes that it's far better to get your caffeine from a natural source rather than from a pill, such as black coffee or tea.

"Seeing as fat-burning pills are essentially concentrated forms of active ingredients, you might be giving your body more than it can handle," he says. "High levels of caffeine can increase anxiety, damage the liver, and result in blood pressure fluctuations."

Claybrook adds if you already drink a lot of caffeine, taking additional caffeine pills likely won't have any effects on your weight loss goals at all.

Green tea extract

Green tea extract is a popular ingredient in weight loss pills thanks to the presence of ECGC, an antioxidant that has been shown to facilitate the body's ability to burn fat. Numerous human studies have shown this to be the case, and best of all, green tea extract is generally well-tolerated and doesn't have many side effects in those not already sensitive to caffeine.

But Masterson notes that as with caffeine pills, it may be even more useful to drink your green tea rather than pop it in pill form—three to five cups a day has been shown to promote weight loss.

Learn how to harness the power of tea to lose weight.


Ephedra is a plant-based supplement that has been used in Traditional Chinese Medicine for hundreds of years. While supplements containing ephedra alkaloids and ephedrine have been shown to be dangerous, ephedra extracts that do not contain ephedrine, despite some worries about their safety, especially for people with high blood pressure, are still sold on the U.S. market today.

One of the biggest name brands in ephedra-based weight loss supplements is Lipodrene, which combines ephedra, green tea extract, caffeine, and hoodia gordonii, a purported appetite suppressant (albeit with limited evidence in favor of its effectiveness).

Lipodrene does have a few side effects, including high blood pressure and difficulty sleeping due to the stimulant nature of its active ingredients.

Another related supplement is bitter orange or synephrine, which has some of the same characteristics of ephedrine and ephedra, albeit in a less potent form.


Better known by brand-names Alli or Xenical, orlistat is a drug that inhibits the breakdown of fat in the gut, essentially keeping your body from absorbing calories from fat. While studies have shown that orlistat definitely helps increase weight loss, it does have some rather unpleasant digestive side effects (after all, that fat has to go somewhere!). Most people taking orlistat find that they have to follow a low-fat diet in order to reduce bowel and digestive problems, including leaky or oily stool. Orlistat can also contribute to deficiency in fat-soluble vitamins and is best taken in tandem with supplements of these essential nutrients.


Glucomannan is a powerful appetite suppressant derived from a fiber found in the konjac yam. It absorbs water when digested, making you feel full and helping you eat fewer calories.

Dunlap notes that appetite suppressants like glucomannan are "the most effective" way to use a fat-burning pill.

"Use one between your meals to keep you from snacking and adding large amounts of calories that most people disregard because it's just a 'snack,'" says Dunlap.

While glucomannan does have a few digestive side effects, including bloating and flatulence, it also has been shown to promote gut health by feeding your gut's good bacteria.

Which fat-burning pills are snake oil?

Unfortunately, some so-called fat-burning pills either don't work or haven't been adequately tested to show they do. While research may someday prove that the pills below are helpful, for the moment, our experts note that there just isn't the proof to back up their claims.

These include:

  • Raspberry ketones
  • Beta-glucans
  • Calcium
  • Fucoxanthin
  • Guar gum
  • Vitamin D
  • Yohimbe
  • Garcina Cambodia
  • Forskolin
  • Chromium
  • Hoodia Gordonii

Many of these supplements, notes Masterson, can also cause adverse effects, including headaches, irregular heartbeat, gastrointestinal symptoms, anxiety, and more.

Instead of relying on fat-burning pills, Masterson recommends making lifestyle changes.

"Fat-burning pills are not the 'magic bullet,' and do not always promote weight loss as promised," he says. "Healthy eating patterns, such as focusing on whole grains, plenty of fruits and veggies, lean protein, and low-fat sources of dairy, can provide you with sustainable weight loss and health success."

Emily Monaco
Emily Monaco is a food and culture writer based in Paris. Read more about Emily
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