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Surprising Side Effects of Taking Weight Loss Supplements, Says Science

Don't rely on these boosts for a killer bod.
FACT CHECKED BY Kiersten Hickman

While the time-tested weight loss practices of diet and exercise see real results, some have tried to speed up the process by introducing some weight loss supplements into their regular eating plan. While these pills, shakes, teas, and more all claim they can help you trim down the fat, many of these products hide some unexpected side effects.

According to the Mayo Clinic, most of the products that claim to help you drop the pounds don't receive any kind of oversight from the FDA, meaning that the claims they make don't have any substantial value. Even if some of these supplements make bold claims, many of the tested weight-loss nutritional add-ins did not perform any better than placebos, making them utterly pointless to take.

While some supplements don't affect your overall physiology, others hide some seriously surprising side effects that you could never see coming. Here's what you need to know, then be sure to read our list of the 15 Underrated Weight Loss Tips That Actually Work.

Oily discharge

weight loss supplements

If you have taken supplements in the past that can help speed up weight loss, you may have experienced digestive issues, bloating, or constipation. All of these expected consequences might not shock anyone who has some history of exploring these supplements. According to the Mayo Clinic, any kinds of weight loss supplements featuring the active ingredient orlistat commonly cause oily anal discharge. Be aware of this particularly unattractive side effect if you use products like Alli and keep an eye out for even more severe issues, like liver failure, associated with orlistat.

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gaba supplement

No one can argue that stimulants can get your metabolism working and can help you burn off the pounds. While this kind of chemical helps jump start and weight loss goals, you can expect to feel severe bouts of anxiety, especially if you take high doses of this style of supplement. According to the National Institutes of Health, bitter orange, caffeine, the notorious weight loss stimulant ephedra, and more can seriously derail any weight loss goal thanks to this unexpected consequence. You can't help your body if you send your mind spiraling, so make sure to avoid this psychological side effect next time you search for weight loss aid.

If you want a way to boost your diet with some dietitian-approved add-ins without risking any strange side effects, check out the 4 Best Weight Loss Pills and Diet Supplements of 2020: Reviewed by the Experts.


Branch chain amino acid supplement

When you want to get serious about weight loss, you might opt to go straight to your physician and request some prescription weight loss medication. These appetite suppressant pills have received the nod of approval from the FDA, but if you go this route, you might encounter a side effect you might never associate with supplements—insomnia.

According to the Cleveland Clinic, a wide range of prescription appetite suppressant medications can severely affect your sleep cycle and keep you awake all night long. When you want to look and feel your best, you don't want to look like you haven't slept in days.

Don't take your good night's sleep for granted. If you have issues getting a quality night's rest, make sure to check out 20 Ways to Double Your Sleep Quality to get the most out of your bedtime.

Irregular heartbeat

vitamin e

When you think of vitamin D, you may not immediately associate it with weight loss, but this vitamin has somehow turned into a weight loss supplement. While the vitamin has no bearing on weight, some obese individuals have been found to lack the nutrient, causing several companies to use it as an active ingredient in their weight loss medications. If you take a supplement that relies on vitamin D, expect to experience arrhythmia, an unintended side effect you do not want to mess with.

Kidney stones

weight loss supplements

When you want to look your best, nothing can put a damper on your image goals like developing kidney stones. Just like vitamin D, some intense dieters have made the flawed connection between calcium intake and losing weight. As a result, these individuals increase their supplements that contain the mineral, putting them at the direct risk of contracting kidney stones. No one wants to experience the pain of passing these calcium deposits, especially when calcium has no ties to weight loss. Avoid this unexpected side effect and avoid any calcium-based supplement masquerading as a weight loss solution.

If you want to up your calcium gains while avoiding kidney stones, make sure to indulge in The 20 Best Calcium-Rich Foods That Aren't Dairy.

Erich Barganier
Erich Barganier is a health and food writer. Read more about Erich