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Bentonite Fact Sheet


Updated June 05, 2014

Jason7825/Wikimedia Commons

What is Bentonite?

Alternate Names: Bentonite clay, montmorillonite

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.

Why Do People Use Bentonite?



Irritable bowel syndrome

Bloating and gas

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. There were no significant adverse events reported.

Dosage Information

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.

Side Effects and Safety

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.


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.

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 Feb 15;21(4):435-44.

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.

PDR Health. Bentonite. <http://www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/ben_0308.shtml>

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