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SynonymsReturn to top

Akipula, aluminium silicate, anhydrous aluminum silicates, askipula, beidellitic montmorillonite, benditos, bioelectrical minerals, chalk, cipula, clay dirt, clay dust, clay lozenges, clay suspension products, clay tablets, colloidal minerals, colloidal trace minerals, fossil farina, humic shale, Indian healing clay, kaolin, kipula, mountain meal, NovaSil, panito del senor (Spanish), plant-derived liquid minerals,  Terra sigillata , tirra santa, white clay, white mud.

EvidenceReturn to top

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Uses based on scientific evidenceGrade*
Fecal incontinence associated with psychiatric disorders (encopresis): clay modeling therapy in children

There is not enough scientific research to support a recommendation for play with modeling clay as an effective therapeutic intervention in children with constipation and encopresis (involuntary bowel movement).
Functional gastrointestinal disorders

There is not enough scientific evidence to recommend the medicinal use of clay by mouth in patients with gastrointestinal disorders. Some clay preparations have been found to be similar to Kaolin® and Kaopectate®, which are used to treat gastrointestinal disturbances including diarrhea. However, overall, there are significant potential risks that accompany the use of clay, including intestinal blockage and injury as well as lead poisoning.
Mercuric chloride poisoning

Clay lozenges have been used historically in the treatment of mercuric chloride poisoning and were officially mentioned in several European pharmacopoeias, including the Royal College, until the middle 19th Century. However, there is not enough scientific evidence to recommend the use of clay by mouth for poisoning at this time, as there is a risk that the clay itself may contain contaminants.
Protection from aflatoxins

Aflatoxins are toxic substances from the fungus  Aspergillis flavus . This fungus infects peanuts, and ingestion of aflatoxins from peanuts and cereals (primarily in warm and humid regions) has been associated with liver cancers in humans and multiple cancers in animals. Phyllosilicate clay has been shown to adhere to aflatoxins in laboratory study, and HSACS clay in animal diets may diminish or block exposure to aflatoxins. However, the risks of chronic clay exposure likely do not justify the potential benefit.

*Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use;
F: Strong scientific evidence against this use.

Grading rationale

Uses based on tradition or theory
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Acidosis (too much acid in the blood), animal bites, blood purification, cancer, constipation, detoxification, diarrhea, dysentery, eye disorders, fevers, heart disorders, menstruation difficulties, nutrition, plague, poisoning, skin fairness, smoking, syphilis, vomiting, vomiting/nausea during pregnancy, water purification, weight loss.

DosingReturn to top

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)
There is not enough scientific evidence to recommend the safe use of clay.

Children (younger than 18 years)
There is not enough scientific evidence to recommend the safe use of clay in children.

SafetyReturn to top

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

There is a lack of clay allergy reports in the available scientific literature. However, in theory, allergy/hypersensitivity to clay, clay products, or constituents of clay may occur.

Side Effects and Warnings
The practice of eating dirt, clay, or other non-nutritious substances is called "pica" or "geophagia," and may occur in early childhood or in mentally handicapped people. Clay or dirt eating has been associated with lead poisoning in infants, children, and pregnant women, with potential risks such as low red blood cell count and brain damage. Death has occurred related to complications of lead poisoning and brain damage after drinking from a glazed clay pitcher. Clay pots containing candy have been recalled in the United States by the U.S. Food and Drug Administration (FDA) due to high levels of lead in the candy, absorbed from the clay pots. Pica may carry a risk of central nervous system damage. The risk of neurolathyrism, a neurodegenerative, irreversible disorder that causes spastic paraparesis of the body leading to paralysis, was reported to quadruple in a case-control study in Ethiopia when cooking grass pea with clay utensils.

Clay products may contain varying amounts of contaminants including aluminum, arsenic, barium, nickel, and titanium. Elevated levels of 2,3,7,8-tetracholorodibenzo-p-dioxin have been found in fish and eggs from chickens fed a diet including clay. Chronic clay eating has also been associated with imbalances of blood chemistry, such as increased calcium or magnesium and decreased iron and potassium. Myopathy due to severe hypokalemia (low blood potassium levels) has been reported in one case report with large quantities of clay ingestion.

In the 19th Century, a condition was described called "Cachexia Africana," including a swollen appearance, enlarged heart, increased urination, and death. Descriptions of people who chronically ate clay in the 19th Century noted skin that was initially dry and shiny, and in late stages of disease, especially in children, skin ulcerations occurred over the arms and legs. Chronic clay eating has also been associated with small gonads (testes) and muscle injury.

Heartburn, gas, loss of appetite, constipation, diarrhea, abdominal pain, bloating, flatulence, and vomiting after meals have been reported with use of clay. Clay eating has also been associated with intestinal blockage and injury, bowel rupture (perforation), formation of stones in the intestine, and enlarged liver/spleen.

It is reported that children with pica are more likely to develop lung infections. Chronic bronchitis, trouble breathing, and infections have been associated with dust exposure in the heavy clay industry. Hookworm infections may result from eating clay. Tetanus contracted from clay has been described in an infant who ate clay, and in a newborn whose umbilical cord was wrapped in clay.

Pregnancy and Breastfeeding
Use of clay during pregnancy or breastfeeding is not recommended. Eating clay during pregnancy may increase the risk of toxemia or complications at birth.

InteractionsReturn to top

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs
When taken together, clay may inhibit the absorption of drugs such as cimetidine (Tagamet®).

Kaolin has been shown to reduce the bioavailability of quinine in laboratory study.

Interactions with Herbs and Dietary Supplements
Clay can interfere with iron absorption.

Methodology Return to top

This monograph was written and peer-reviewed by members of the Senior Editorial Board of the Natural Standard Research Collaboration ( Dawn Costa, BA, BS (Natural Standard Research Collaboration); Shaina Tanguay-Colucci, BS (Natural Standard Research Collaboration); Catherine Ulbricht, PharmD (Massachusetts General Hospital); Wendy Weissner, BA (Natural Standard Research Collaboration).

Methodology details

Selected references Return to top

  1. Feldman PC, Villanueva S, Lanne V, et al. Use of play with clay to treat children with intractable encopresis. J Pediatr 1993;122(3):483-488.
  2. Fredj G, Farinotti R, Salvadori C, et al. [Topical digestive drugs with a clay base. Influence on the absorption of cimetidine]. Therapie 1986;41(1):23-25.
  3. Gonzalez JJ, Owens W, Ungaro PC, et al. Clay ingestion: a rare cause of hypokalemia. Ann Intern Med 1982;97(1):65-66.
  4. Love RG, Waclawski ER, Maclaren WM, et al. Risks of respiratory disease in the heavy clay industry. Occup.Environ.Med 1999;56(2):124-133.
  5. Montoya-Cabrera MA, Hernandex-Zamora A, Portilla-Aguilar J, et al. [Fatal lead poisoning caused by the ingestion of lemonade from glazed clay chinaware]. Gac Med Mex 1981;117(4):154-158.
  6. Obialo CI, Crowell AK, Wen XJ, et al. Clay pica has no hematologic or metabolic correlate in chronic hemodialysis patients. J Ren Nutr 2001;11(1):32-36.
  7. Pariente EA, De La Garoullaye G. [A multicenter comparative study of a mucilage (Karaya gum + PVPP) versus clay in functional intestinal disorders]. Med Chir Dig 1994;23(3):193-199.
  8. Phillips TD, Sarr AB, Grant PG. Selective chemisorption and detoxification of aflatoxins by phyllosilicate clay. Nat Toxins 1995;3(4):204-213.
  9. Phillips TD. Dietary clay in the chemoprevention of aflatoxin-induced disease. Toxicol Sci 1999;52(2 Suppl):118-126.
  10. Severance HW Jr, Holt T, Patrone NA, et al. Profound muscle weakness and hypokalemia due to clay ingestion. South Med J 1988;81(2):272-274.
  11. Wang JS, Luo H, Billam M, et al. Short-term safety evaluation of processed calcium montmorillonite clay (NovaSil) in humans. Food Addit Contam 2005 Mar;22(3):270-9.

January 01, 2008.

Natural Standard Logo This evidence-based monograph was prepared by the Natural Standard Research Collaboration. The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. Talk to your health care provider before taking any prescription or over the counter drugs (including any herbal medicines or supplements) or following any treatment or regimen. Copyright© 2008 Natural Standard ( All Rights Reserved.