Side Effects of Herbal Weight-Loss Supplements: What do Clinical Studies Show?
Herbal remedies claim to be safe and effective for weight loss, but herbal dietary supplements aren’t held to the same standards as conventional drugs. As a result, these weight-loss supplements might not accurately warn of unpleasant—or even dangerous—side effects.
A 2005 research review collected clinical data on several popular weight-loss herbs and evaluated their side effects. The researchers retrieved information from databases (such as Medline), the World Health Organization, medical journals and their own files. After reviewing the most relevant studies, they found that the side effects of some herbal weight-loss supplements are risky enough to outweigh the benefits.
Some Herbs Have Negative Effects
Most of the supplements reviewed had negative side effects. While some have effects that are less severe than others—bloating and gas, for example—other herbal supplements have more dangerous effects such as hepatic injury and even death.
- Ephedra, also known as ma huang, has such risky side effects that it has been banned in the United States. It’s known to have unpleasant effects on the central nervous and cardiovascular systems, such as heart palpitations and psychiatric issues.
- Guarana contains large amounts of caffeine, so its side effects are similar to caffeine’s. It can cause heart palpitations, anxiety, irritability and various effects on the central nervous system.
- Yohimbe has been repeatedly shown to have negative effects including anxiety, agitation and high blood pressure. One case study reported severe headache and high blood pressure.
Psyllium can cause unpleasant gastrointestinal effects like bloating, upset stomach and gas.
Some Herbs Aren’t Associated with Adverse Side Effects
Other supplements haven’t yet been associated with serious side effects, either because none exist or because existing data is insufficient.
- Garcinia Cambogia is an appetite suppressant and stops the body from absorbing as much fat. Clinical trials have reported few side effects, none of them serious.
- Yerba mate can’t be associated with side effects because it hasn’t been studied enough. Participants in the 2001 study by Dr Anderson did not show any side effects. It’s usually consumed as a hot drink and may be linked to esophageal cancer, but the most likely cause is not the herbal itself but the prolonged exposure of the esophagus to the high temperature the Yerba mate beverage.
Are Herbal Weight-Loss Supplements Safe?
According to the study, many herbal supplements have unpleasant effects associated with them, but it’s not clear yet whether the supplements themselves are the cause. Despite being useful for showing what effects have occurred, the clinical data aren’t complete enough to prove that herbal weight-loss supplements are responsible for the side effects.
Still, a lack of clear proof doesn’t mean that the supplements are safe. The side effects reported in trials are a good reason to suspect that herbal weight-loss supplements are potentially dangerous. As tempting as the promises on the bottles might be, you should consider avoiding herbal diet aids unless they’re proven to be safe.
Disclosure: We review and test many products on this site. Nobody pays us to review their product. However, if you end up purchasing one of these products we sometimes receive a small fee from the merchant. This helps to keep the site maintained and running.