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Limited evidenceGut health

Bentonite Clay

Edible clay does adsorb certain toxins — the real evidence is for binding aflatoxin in contaminated food supplies — but there is no credible support for the 'pulls toxins and heavy metals out of your body' detox claims, and clay products have themselves been recalled for lead contamination.

What the science says

  • Binds aflatoxin and reduces its absorption Moderate evidence

    This is the one genuine indication. Randomized placebo-controlled trials of calcium montmorillonite clay (NovaSil, 1.5-3 g/day for 3 months) in Ghanaian adults at high aflatoxin exposure reduced urinary aflatoxin M1 biomarkers by roughly 50-60% without disturbing serum vitamins A and E or key minerals. It works by binding aflatoxin in the gut lumen before absorption — relevant to populations eating contaminated maize and groundnuts, not to a Western 'detox' regimen.

  • Detoxifies heavy metals from the body Limited evidence

    No human trial shows that oral bentonite lowers blood or bone lead, mercury or cadmium. The claim is inverted in practice: the FDA has issued consumer warnings and recalls after finding elevated lead in marketed bentonite clay products, and clay-eating (geophagy) is itself a documented cause of lead poisoning, including severe cases in pregnancy.

  • Improves IBS, diarrhea or 'gut cleansing' Limited evidence

    Clay is an adsorbent and can firm stool, and smectite clays (diosmectite) are used as antidiarrheals in some countries with reasonable trial support for acute diarrhea in children. That does not extend to bentonite drinks for bloating or IBS in healthy adults, where controlled evidence is absent and the more likely consequence of chronic use is constipation and reduced nutrient absorption.

Dosage & safety

Studied doseAflatoxin-binding trials used 1.5-3 g/day of pharmaceutical-grade calcium montmorillonite (NovaSil), taken with meals, for up to 3 months. Consumer 'detox' products suggest 1-2 teaspoons (roughly 5-10 g) daily in water — a higher dose than the studied one, with no supporting evidence and greater risk of binding nutrients and drugs.
SafetyConstipation, bloating and reduced absorption of iron, zinc and other minerals with chronic use. Clay is nonspecific — it binds medications too, so separate from all drugs and supplements by at least 2-3 hours. Serious risk of intestinal obstruction if taken with inadequate fluid. Product contamination is the central safety issue: FDA testing has found elevated lead in some bentonite clay supplements, and case reports link chronic clay ingestion to lead poisoning and severe hypokalemia. Avoid in pregnancy, in children, and in anyone with iron deficiency or bowel motility disorders. Do not use as a substitute for medical treatment of poisoning — activated charcoal, not bentonite, is the emergency room adsorbent.

Scientific references

Where to buy

Pure Body Naturals, Indian Healing Bentonite Clay, 8 oz (227 g)

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