Antiperspirants are made with aluminum chloride and other aluminum compounds that can block the opening of sweat glands to control excessive sweating.
In the past, there were some concerns that antiperspirants could be linked to breast cancer. But these claims have since been disproven, and there is no clear evidence that using antiperspirants increases your risk of cancer.
Here's what you should know about the safety and health risks of antiperspirants.
Rumors from the early 2000s linked antiperspirant use to breast cancer, but there are no strong studies to support this claim, says Kiran Mian, DO, a dermatologist in New York.
"This came about as most breast cancers arise in the upper outer quadrant of the breast, the area closest to the axilla [armpit] where antiperspirant is applied," Mian says. "It was thought that antiperspirant contained carcinogens that absorbed into the skin via razor nicks and caused mutations leading to cancer."
Basically, some people thought that aluminum — the active ingredient in antiperspirants — could increase the risk of cancer. To address the rumors, a team of researchers at Fred Hutchinson Cancer Research Center conducted a study involving 793 women with no history of breast cancer and 813 women with breast cancer.
They published their results in 2002, showing that there was no increased rate of breast cancer for those who regularly used an antiperspirant, deodorant, or shaved their underarms.
A 2014 review concluded that there was no clear evidence connecting the use of antiperspirants to a higher risk of breast cancer.
Aluminum compounds are one of the main active ingredients in antiperspirants that help to combat sweat.
There is little evidence to suggest that aluminum gets absorbed through the skin in any significant quantity from antiperspirants, Mian says. Most healthy people will be able to deal with the small amount of aluminum that could enter their system.
However, antiperspirant may come with potential risks for people with kidney disease, because their kidneys may not be able to deal with aluminum as effectively.
And because high aluminum levels in your body can increase the risk of developing dementia, the FDA requires antiperspirant labels to carry a warning for those with kidney disease to consult with their doctor before use.
This accumulation of aluminum only happens in patients with advanced kidney disease or kidney function of less than 30%. In people without kidney disease, it's nearly impossible to absorb enough aluminum through the skin to harm your kidneys, according to the National Kidney Foundation.
Parabens are another ingredient commonly found in antiperspirants. These preservatives are used in many personal care products and have weak estrogen-like properties, Mian says, meaning they mimic estrogen and have the potential to disrupt hormone function.
Because estrogen is the hormone responsible for the growth and division of breast tissue, some people have theorized that parabens may be linked to breast cancer.
"Parabens have been found in breast cancer tissue, however, whether their presence has any significance is not known," Mian says. "Although parabens do show weak-estrogen properties, natural estrogen is thousands of folds stronger, and much more likely responsible for breast cancer development."
To use antiperspirants safely, always follow the label instructions. Apply a thin coat to the armpits at night before bed, as this allows the aluminum salts to form plugs that block sweat gland openings.
If you think you may have a potential allergy to any antiperspirant ingredients, you may want to do a test spot — apply the antiperspirant to a small area on the inner wrist and watch for a reaction, like an itchy or bumpy rash.
If you experience a reaction, contact your doctor, who can prescribe a topical cream to treat the rash. Your doctor might also suggest patch testing to determine which chemical in the product you are allergic to so you can avoid it.
According to the National Cancer Institute, antiperspirants are safe to use and no studies have confirmed a direct link between these products and cancer or other negative health effects. You may want to check with your doctor if you're worried about your kidney function, but overall, antiperspirants are very safe.