Is clay as good for your insides as your skin?

A spoonful of clay a day keeps the impurities away… or at least that’s what advocates of the clay cleanse claim, including actresses Shailene Woodley and Zoe Kravitz.

The treatment is nothing new though, with volcanic ash having been used in healing practices for centuries.

Perry Arledge, author of “Living Clay, Nature’s Own Miracle Cure,” explains that clay “is like a Pac-Man gobbling up all the waste… basically cleaning house from the mouth south.”

The logic is that it works inside your body the same way it does on the outside: Clay is a common ingredient in face masks and spa body wraps. It’s thought to sweep away newly absorbed toxins, neutralize acidity, soothe inflammation and cleanse the colon to boost the absorption of vitamins and nutrients.

For all those good properties, eating clay can come with some downsides. “The Herxheimer reaction is a short-term detoxification reaction in the body. It is caused by the release of toxic chemicals from the cell walls of dying bacteria due to effective treatment,” Arledge warns. There’s also a risk of iron deficiency, so clay cleanses aren’t meant to be done long-term, and you have to make sure to keep hydrated while on the cleanse.

As the body detoxifies, it is not uncommon to experience flu-like symptoms including headaches, general malaise, sweating, chills or nausea. Constipation is another common symptomfor about 20 percent of people.

It may also change your bowel movements in an unusual way, taking on a metallic smell.

The other downer for the product is that it could, ironically, be detrimental to your health, with the U.K.’s Food Standards Agency issuing a warning about clay after high levels of lead and arsenic were discovered in some products.

To see if this detox is worth the hype, I tried a week-long cure of Cattier Superfine Green Clay. It is montmorillonite clay, one type that is usually used internally, like kaolin and bentonite. One important note: Skip the cleanse if you’re on any medication.

The recipe is easy: Stir one tablespoon of clay into a glass of water, using a thick glass and a wooden spoon — it is thought that clay loses its properties through contact with metal. Let the mixture sit overnight. In the morning, drink the water but not the clay deposit.

To avoid the feeling that I’m drinking puddle water, I left the glass in the fridge. When I first tried it, I tasted its earthiness, but nothing overwhelming. That said, after a week, the morning clay shot was becoming more and more difficult to handle. I didn’t notice a strong detoxifying effect; maybe I didn’t really need a detox at that time.

There was one big benefit. I had a bad stomach ache one night, and the next morning I skipped breakfast but took my daily dose of clay. After that, the pain was gone. Clay is probably not my detox ingredient of choice, but I’ll definitely have it again to cure some pain in my gut.