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Supplements for Weight Loss



Glucomannan is made from the konjac plant. Like other dietary fibers, it is supposed to help people lose weight by blocking the absorption of dietary fat.

Very preliminary evidence suggests it might be helpful for weight loss. But other evidence shows no effect.

The Natural Medicines Comprehensive Database says there is "insufficient evidence" to rate the effectiveness of glucomannan for weight loss.

Glucomannan must be taken with at least 8 ounces of water. Taking it without water, especially in tablet form, could lead to choking or blockage of the:

  • throat
  • esophagus
  • intestine

Taking glucomannan in powder form appears to be safer.

Glucomannan also may make it harder for your body to absorb medications. So people should take medications either 1 hour before or 4 hours after taking glucomannan or other fibrous products.

Green Tea Extract

Green tea extract supposedly works by:

  • curbing appetite
  • raising calorie and fat metabolism

The Natural Medicines Comprehensive Database says there is not enough evidence to rate the effectiveness of green tea for weight loss.

Side effects of green tea extract, especially when consumed in high amounts, include:

  • nausea
  • vomiting
  • bloating
  • gas
  • diarrhea
  • dizziness
  • insomnia
  • agitation

Green Coffee Extract

Green coffee is thought to decrease body fat and help weight loss.

Early research suggests it may lead to modest weight loss. More research is needed to better determine the effects, but the Natural Medicines Comprehensive Database rates it as “possibly effective” for weight loss.

Few people have side effects, but because of the caffeine in green coffee it may cause:

  • headaches
  • stomach upset
  • nervousness
  • insomnia
  • abnormal heart rhythms

Guar Gum

Guar gum comes from the seed of the guar plant. Like other dietary fibers, it is said to work by preventing the absorption of fats and helping you feel full.

Guar gum has been studied more extensively than other fibers for weight loss. Most researchers have concluded that it is ineffective.

The Natural Medicines Comprehensive Database says that guar gum is "possibly ineffective."

Side effects may include:

  • gas
  • diarrhea



Hoodia is a plant that grows in the Kalahari Desert in Africa. According to the National Center for Complementary and Alternative Medicine, the stem of the root was traditionally used by Bushmen to reduce hunger and thirst during long hunts. It's marketed for weight loss as an appetite suppressant.

Hoodia contains P57, an ingredient said to suppress appetite by helping you feel full. But there is no credible evidence that it's safe or effective.

The Natural Medicines Comprehensive Database says it has insufficient evidence to rate the effectiveness of hoodia.

WebMD Medical Reference

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