What Hydrogen Peroxide Can (and Can't) Do for Your Health

With its signature meh-looking brown bottle, hydrogen peroxide is hardly an exciting product to score at your local drugstore. But the chemical compound has popped up on TikTok lately as a trendy way to whiten your teeth. In a viral TikTok, someone shows themselves dipping a cotton swab in 3% hydrogen peroxide and using it to whiten their teeth.

Teeth whitening isn't the only hydrogen peroxide hack people are raving about online, though. Some claim it can also be used to remove ear wax, and even to treat bacterial vaginosis.

But…is any of this legit? Here's what you need to know about hydrogen peroxide's uses for your health.

First, what is hydrogen peroxide, exactly?

Hydrogen peroxide is a chemical compound that presents as a colorless, slightly viscous liquid. "The chemical formula is H₂O₂," says Jamie Alan, Ph.D., an assistant professor of pharmacology and toxicology at Michigan State University. In other words, hydrogen peroxide is basically water, plus one extra oxygen atom, which allows it to react with other agents. You're probably most familiar with hydrogen peroxide as a cleaning agent that can sterilize wounds or disinfect your home, but it can also be used to bleach clothes, hair, and yes, teeth (more on that soon), explains Alan.

Generally speaking, hydrogen peroxide is "pretty safe," adds Alan, which might help explain why it's touted for so many different uses. That said, the Food and Drug Administration notes that getting hydrogen peroxide on your skin may cause irritation, burning, and blistering. The FDA also says that getting hydrogen peroxide in your eyes can cause burning, and that breathing in the fumes may potentially cause chest tightness and shortness of breath. You definitely don't want to ingest (read: drink) hydrogen peroxide either, as that might lead to vomiting and general gastric distress, according to the FDA.

You can use hydrogen peroxide on your teeth, but it's not really recommended.

Thanks to hydrogen peroxide's bleaching properties, yes, you can technically use 3% hydrogen peroxide to break down stains on your teeth and achieve a whitening effect (as you saw in that viral TikTok), says Julie Cho, D.M.D., a dentist in New York City and a member of the American Dental Association. But, notes Dr. Cho, you want to proceed with caution.

"Yes, you can use hydrogen peroxide for whitening teeth," she explains. "In fact, dental office whitening agents contain 15% to 38% hydrogen peroxide. The home kits have a lower concentration of hydrogen peroxide (usually 3% to 10%,) or they may contain carbamide peroxide, which is a derivative of hydrogen peroxide."

But the higher the concentration of hydrogen peroxide, the higher the chance it can lead to tooth sensitivity and cytotoxicity (i.e. kill cells), which can damage your teeth. "[That's why] you want to be cautious," stresses Dr. Cho.

While you can technically try this hack, Dr. Cho says you really shouldn't. "I would recommend against using straight hydrogen peroxide to whiten teeth," she says. "There are hundreds of bleaching products over the counter, which are specifically manufactured to whiten teeth. It's just as easy and inexpensive to use an OTC peroxide-infused bleach." (See: The Best Whitening Toothpaste for a Brighter Smile, According to Dentists)

Dr. Cho also recommends rinsing with an OTC hydrogen peroxide mouthwash, such as Colgate Optic White Whitening Mouthwash (Buy It, $6, amazon.com). "Another option is to use whitening strips or trays that [contain] hydrogen peroxide," which are gentler than straight hydrogen peroxide, she says.

As for how often you can safely use whitening strips or a whitening treatment, typically, results can last anywhere from six months to two years, depending on your teeth and what you used, notes Dr. Cho. It's best to consult your dentist directly about how often you use teeth whitening products, regardless of the ingredients.

You can also use hydrogen peroxide in your ear.

You've probably heard by now that using a cotton swab to dig out ear wax isn't a good idea (it can actually push wax deeper into your ear canal rather than remove it). Instead, it's recommended that you use drops — such as baby oil, mineral oil, or commercial ear wax drops — to try to soften ear wax and then let it drain out, according to the U.S. National Library of Medicine.

"[But] one of the easiest remedies for ear wax is just regular hydrogen peroxide," suggests Gregory Levitin, M.D., an otolaryngologist at New York Eye and Ear Infirmary of Mount Sinai. Usually, the small hairs inside your ear canal lift and bring wax out on their own, but sometimes the wax can be heavier, excessive, or just build up over time, says Dr. Levitin. In those cases, "hydrogen peroxide can help loosen any wax that adheres to the ear canal, and then it simply washes out on its own," he explains.

To try ear wax removal with hydrogen peroxide, apply a few drops of the chemical compound to the ear canal, let it sit for a moment with the ear tilted up to let the hydrogen peroxide run into the canal, and then tilt back down to let the liquid drain out. "It's that simple and can minimize and prevent excess wax build-up," Dr. Levitin says. "There's no need for any special instruments or sections." Just make sure you're using a safe concentration of hydrogen peroxide: OTC hydrogen peroxide, which is usually a 3% concentration, is fine to use for ear wax removal, notes Dr. Levitin.

While this is a generally safe method of cleaning your ears, Dr. Levitin doesn't recommend doing it often — your ears use wax to protect themselves, after all — so be sure to talk to your doc about what makes the most sense for your personal care routine.

Some people also claim you can use hydrogen peroxide for ear infections, but that's not true, says Dr. Levitin. "Ear infections of the ear canal that are due to a bacteria or fungus should be treated by an ear, nose, and throat doctor or medical professional with antibiotic drops," he says. But, he adds, there may be some use for hydrogen peroxide after the infection is treated. "After the infection has cleared, there is often residual dead skin or debris, and hydrogen peroxide can certainly help to clear this up in a similar fashion as ear wax," Dr. Levitin says.

Research is mixed on using hydrogen peroxide to treat bacterial vaginosis.

In case you're not familiar with it, bacterial vaginosis is a condition caused by a change in the amount (usually an overgrowth) of certain types of bacteria that normally live in the vagina. BV symptoms typically include vaginal irritation, itching, burning, and "fishy"-smelling discharge.

The infection is usually treated with antibiotics, though some people claim online that you can treat BV by soaking a tampon with hydrogen peroxide and inserting it into your vagina. But there are "mixed opinions" in the medical community about this method, says women's health expert Jennifer Wider, M.D.

Some smaller, older studies have found a benefit. In a 2003 study of 58 women with recurring BV that wasn't responding to antibiotic treatment, the women were given 30 mL of 3% hydrogen peroxide via vaginal irrigation (aka douching) every evening for one week. During a three-month follow-up, researchers found that the treatment eliminated BV's signature "fishy" smell in 89% of the women. "Hydrogen peroxide represents a valid alternative to conventional treatments for recurrent bacterial vaginosis," the study authors concluded. However, it's worth noting that experts overwhelmingly recommend against douching in any context, as it can increase your risk of pelvic inflammatory disease and other infections.

In another (even older and smaller) study, researchers asked 23 women with BV to do a vaginal "washout" (again: douche) with 3% hydrogen peroxide, let it sit for three minutes, and then drain it out. BV symptoms cleared completely in 78% of the women, improved in 13%, and remained the same in 9% of the women.

Again, though, this isn't something doctors are rushing to recommend. "These are small studies, and the use of hydrogen peroxide in the treatment of BV could use a larger study to back up these claims," Dr. Wider says. She also notes that using hydrogen peroxide in your vagina could "cause vaginal and vulvar irritation and could potentially disrupt the pH balance by killing off the good bacteria along with the bad." (Here's why your vaginal bacteria is important to your health.)

Overall, if you're into the idea of using hydrogen peroxide for something other than what's on the label, it's not a bad idea to check in with your doctor first, just to be on the safe side.