Bentonite clay, a highly absorbent clay with numerous health and beauty applications, is used in some alternative treatments for acne and other similar skin problems. It is commercially available without a prescription in a powdered form that can be moistened and used topically to address the most common causes of acne vulgaris.
The primary causes of acne vulgaris, according to the Mayo Clinic, are excess skin oil production, bacteria and abnormal shedding of dead skin cells. Sometimes, due to hormones, heredity, medication and other factors, a person's skin produces too much sebum, the natural oil the body uses to keep skin from getting too dry. The excess sebum can cause blockage within a hair follicle on the skin, producing a whitehead or blackhead. Skin that is oily with sebum encourages production of bacteria that can irritate the skin, and further irritation and pore blockages can occur when dying skin cells fail to be shed through the skin's natural exfoliation process.
Bentonite Clay Properties
Bentonite clay, also called Montmorillonite, is a quarry-mined natural clay that is extracted from active deposits in Wyoming, Montana and elsewhere, according to botanical.com. It is highly absorbent, and when it becomes saturated with liquid, it develops a mild electrical charge that helps it to draw toxins, heavy metals and other impurities away from tissue. These absorbed particles are then bound by the electrical charge, preventing them from being re-absorbed into the tissue.
As an acne treatment, bentonite clay is most commonly used as a wet clay mask that is applied to facial skin with the fingers and left to dry for about 15 minutes. Its absorbent quality helps wick excess sebum from the skin, and its astringent properties work to shrink and tighten irritated and enlarged pores. The textbook "The Complete Technology Book on Herbal Beauty Products with Formulations and Processes" recommends a mix of one tablespoon powdered bentonite clay, one tablespoon comfrey leaf tea, one teaspoon ground elder flowers, one teaspoon ground strawberry leaves and one drop of lavender essential oil as a soothing mask for acne-prone skin. Powdered bentonite clay can also be mixed with water alone or any other combination of ingredients that includes a liquid.
Bentonite clay can also be used to measure a person's sebum production rate, which may be helpful in diagnosing clinical acne vulgaris or distinguishing it from other oily skin conditions, according to William J. Cunliffe's book, "Acne." Using the "bentonite technique," a clinician can apply a small patch of wet bentonite clay to the same patch of skin on a single subject for multiple three-hour intervals over a 24-hour period. Each patch is removed after three hours and examined using thin-layer chromatography to determine how much sebum was absorbed during that period. Trials using this method have found that samples taken over the first 12 hours showed decreasing sebum levels, and that sebum levels evened-off over the last 12 hours. Physicians have hypothesized that the clay absorbs accumulated sebum over the first half of the testing period, and when this amount is exhausted, the subsequent samples reveal amounts that lead to the actual real-time sebum production rate of the subjects.
Because bentonite clay absorbs moisture from the skin and has astringent properties, using bentonite mask treatments may expose you to the risk of over-dry skin. Depending on your skin type, you can use various types of liquids to hydrate the bentonite powder so as not to over-dry your specific skin, according to "The Dictionary of Wholesome Foods" by Embree De Persiis Vona, Anstice Carroll and Gianna De Persiis Vona. If you have very oily skin, you can mix the bentonite powder with water. Those with normal skin may avoid over-drying by mixing the powder with milk, and those with naturally dry skin may need to mix the powder with a heavy cream in order to keep their skin properly hydrated.