How Worried Should I Be About Aluminum in My Deodorant?

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With the growing number of deodorant brands prominently advertising their products as aluminum-free, it’s easy to understand how one might conclude: aluminum, bad, aluminum-free, good. But, as anyone who spends any amount of time trying to decipher personal-care ingredient labels and descriptions knows, that’s not always how beauty marketing works. So, is aluminum-free deodorant something we should all be seeking out for our collective safety? Or is this a case of beauty marketing problem-solving for a problem that doesn’t really exist?

First, let’s consider what a deodorant is and also, importantly, what it isn’t. Deodorants are designed to minimize, neutralize, and mask underarm odor — not to actually stop sweat — and are not regulated as a drug, which means no one’s monitoring what ingredients are in their formulas. This isn’t true with antiperspirants, which do stop sweat: They are classified as over-the-counter drug products and are regulated by the FDA. So, although anything slathered across our underarms is commonly referred to as deodorant, there is a distinction, and aluminum is at the heart of that distinction: any product that bills itself as an anti-perspirant will have aluminum somewhere on the label.

Aluminum salts have long been the main category of ingredients used in antiperspirant products because of their dual benefits, says cosmetic chemist Victoria Fu of Chemist Confessions, who co-founded the site with Gloria Lu. “These salts dissolve into sweat and ultimately form a temporary plug in the sweat gland to prevent sweating,” she says. “They also act as an antimicrobial, which helps to control odor-causing bacteria.”

If you’re picking up a deodorants marketed as “clean” or “natural,” it uses non-aluminum ingredients to mask odor (like tea-tree oil, coconut oil, sage, yeast ferments, and apple cider vinegar) and try to absorb sweat (like baking-soda arrowroot powder and corn or tapioca starch). But, “these ingredients don’t actually block sweating,” says Rebecca Marcus, MD, a board-certified dermatologist in Dallas and founder of Maei MD. Instead, they can help prevent wetness by absorbing moisture (at least for some people — their efficacy tends to vary wildly).

Aluminum’s vilification as a deodorant ingredient is decades old. Lu says that in the ’80s aluminum accumulation was being looked at as a possible culprit in the neurodegenerative process (which can cause Alzheimer’s) and in the early aughts a hypothesis began to circulate linking antiperspirants containing aluminum to the rise of breast cancer (because of the close proximity to breast tissue). Aluminum is an estrogenic metal, which means “it influences estrogen receptors in human cells, and therefore the risk is an estrogen-responsive breast cancer,” says New York dermatologist Julie Russak, MD. But, she continues, the risk is theoretical; there aren’t any studies proving it. “It doesn’t translate to actual use of aluminum deodorants, since the application method and pathway are very different,” Lu adds.

In fact, numerous studies dating back to 2008 have debunked the theories about aluminum’s link to cancer — the most important aluminum review, says Fu, was done by the E.U. SCCS in 2014, where cosmetic-regulating bodies investigated and deemed aluminum-based deodorants safe. The American Cancer Society has said the same. Only people with significantly diminished kidney function should be discouraged from using a deodorant with aluminum because “they’re unable to filter aluminum from the blood via urine,” says Marcus. To wit, if you look at most deodorant labels, there’s a line that says: “Ask a doctor before use if you have kidney disease.”

For the rest of us, there are other reasons to choose a so-called natural deodorant over a conventional antiperspirant. There’s skin irritation. While aluminum salts have been proven to be safe and effective, that doesn’t mean that some people may not find them irritating. For them, aluminum-free formulas may be a great option, particularly if you’re looking primarily to mask or neutralize odor, instead of to stop sweat. Though, Marcus points out, it’s often the “natural” deodorants made with essential oils that may irritate thin, delicate armpit skin — particularly if you shave the area as well. Many dermatologists will steer sensitive-skinned patients to fragrance-free deodorants (like Vanicream, which has aluminum, or Schmidt’s, which doesn’t). For those with armpits unbothered by scent, “natural” brands (like Corpus Naturals, Saltair, Evolve Together, Native) offer more sophisticated fragrances than their conventional drugstore counterparts.

One major motivating factor for some to go “natural” may not have to do with a perceived risk of what aluminum may do to the body, but what it will do to your clothes. A chemical reaction that happens between the aluminum in antiperspirants and your sweat, “can cause yellow stains on white clothing,” Marcus confirms. If your wardrobe is dominated by white, your deodorant decision may be an easy one. But the truth is that how you choose a deodorant is entirely subjective — just like the decision to forego it entirely.