“You can get irritation or allergic rashes, and that’s far and away the more common health issue seen with deodorants — all deodorants, whether traditional or natural,” said Dr. Jennifer Chen, a clinical associate professor of dermatology at Stanford Medicine. The most common issue with deodorant is irritant contact dermatitis, or skin irritation, Dr. Chen said, which “usually can’t be pinned down to a specific ingredient, even though some ingredients are more irritating than others.”
The most troublesome ingredient in any kind of deodorant or antiperspirant, whether it’s “natural” or not, is fragrance, said Dr. Nina Botto, an associate professor of dermatology at the University of California, San Francisco. This includes essential oils, which many natural deodorant brands play up in their marketing. “Botanicals, plant extracts and essential oils are often touted as having health benefits,” Dr. Botto said. “But those natural components actually cause a lot of health problems and trouble for the skin.”
The combination of the underarm’s thin, folding skin, hair follicles and moist environment makes this area of the body more susceptible to irritation or an allergic reaction compared to, say, if you put deodorant on your back. In fact, Dr. Chen noted, one study on fragrance allergies found that among many of the scented personal care products tested — like scented deodorants, lotions, shampoos, shaving creams and hair dyes — the deodorants caused the most cases of allergic contact dermatitis, a skin rash caused by contact with an allergen.
Dr. Botto said that while she still sees allergic reactions to synthetic fragrances, she’s been getting more and more patients who are dealing with allergic contact dermatitis after using products with natural fragrance, like those containing linalool and limonene — natural compounds extracted from certain plants, like citrus fruit peels, which are commonly used in natural deodorants.
Even worse, “a lot of times you’ll see that someone gets a rash with a natural deodorant and they’ll put on balms and other ‘natural’ remedies that contain more of the same ingredients,” Dr. Botto said. “It’s kind of like adding gasoline to a fire.” She noted that such rashes can also cause breaks in the skin, which can then lead to infection. “It can be a real mess,” she said.