Bentonite Clay Health Benefits and Side Effects

Bentonite is a clay that is available in supplement form. The primary ingredient in bentonite is hydrated aluminum silicate. Other constituents in bentonite include calcium, magnesium, and iron (the composition varies according to the geographical location in which it is found).

Once in the body, bentonite easily absorbs water. It remains in the digestive tract and is believed to bind and inactivate toxins and promote their excretion.

Alternate Names: Bentonite clay, montmorillonite

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In alternative medicine, bentonite is used for the following purposes:

A large double-blind, placebo-controlled study examined the use of bentonite clay in people with irritable bowel syndrome. Bentonite appeared to work best for people with constipation-predominant IBS. People taking the bentonite clay experienced a significant improvement in abdominal discomfort and pain. Bentonite users also reported significantly better symptom reduction and treatment efficacy with bentonite. However, this study has not been replicated.

Bentonite is available in liquid or powder form. It is a popular ingredient in colon cleanse products.


Bentonite should be taken with plenty of water to avoid intestinal obstruction or constipation.

Pregnant or nursing women and the elderly should avoid bentonite. Bentonite should not be taken two hours before or after medication or nutritional supplements.

Although there haven't been adverse effects in amounts used in nutritional supplements, there are no studies on the long-term safety of bentonite in humans.

It's important to keep in mind that supplements haven't been tested for safety, and dietary supplements in general are largely unregulated. In some cases, the product may deliver doses that differ from the specified amount for each herb. In other cases, the product may be contaminated with other substances, such as metals, including lead. Also, the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established.

Using Bentonite for Health

Due to the limited research, it's too soon to recommend bentonite as a treatment for any condition. It's also important to note that self-treating a condition and avoiding or delaying standard care may have serious consequences. If you're considering using bentonite for any health purpose, make sure to consult your physician first.

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Article Sources
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  1. Williams LB, Haydel SE. Evaluation of the medicinal use of clay minerals as antibacterial agents. Int Geol Rev. 2010;52(7/8):745-770. doi:10.1080/00206811003679737

  2. Ducrotte P, Dapoigny M, Bonaz B, Siproudhis L. Symptomatic efficacy of beidellitic montmorillonite in irritable bowel syndrome: a randomized, controlled trial. Aliment Pharmacol Ther. 2005;21(4):435-44. doi:10.1111/j.1365-2036.2005.02330.x

  3. FDA. FDA warns consumers not to use “Best Bentonite Clay.” Updated March 23, 2016.

Additional Reading
  • Abdel-Wahhab MA, Nada SA, Farag IM, et al. Potential Protective Effect of HSCAS and Bentonite Against Dietary Aflatoxicosis in Rat: With Special Reference to Chromosomal Aberrations. Nat Toxins.1998; 6:211-218.

  • PDR Health. Bentonite.

  • Santurio JM, Mallmann CA, Rosa AP, et al. Effect of Sodium Bentonite on the Performance and Blood Variables of Broiler Chickens Intoxicated With Aflatoxins. Br Poult Sci. 1999; 40:115-119.