Is Hydrogen Peroxide Mouthwash Safe to Use?

Imagine this scenario. You’ve just finished flossing and brushing your teeth when, as you reach into your medicine cabinet to get your mouthwash, you make a heartbreaking discovery. Your big one-litre bottle of mouthwash is all empty. Your twice-daily oral care routine is now as good as mud. There will be no peppermint-fresh, spearmint-pure, alpine-pristine smile for you. Unless… what’s that lurking behind the empty bottle of mouthwash? Why, it’s the hydrogen peroxide you bought ages ago then used once, and totally forgot about! Your smile is saved! Or is it?

When used properly, hydrogen peroxide is great for cleaning and disinfecting our homes—and even, sometimes, minor cuts and scrapes. But the question you’re now faced with is whether or not it also makes for a safe and effective oral rinse.

If you’ve ever gone to the dentist to have your teeth whitened, then you would likely know that dentists store and use hydrogen peroxide. Quite apart from its whitening effect on our teeth, dentists value this chemical compound for its antibacterial properties. Right about now, you might be thinking that you’ve found the perfect teeth whitening mouthwash and that you can finally finish your oral care routine. But before you go and improvise an oral concoction, read this quick guide to hydrogen peroxide mouthwash—you just might have to run out to the drug store after all.

What is Hydrogen Peroxide?

Hydrogen peroxide (H2O2) is an oxidizing chemical compound with antiviral, antiseptic, and antibacterial properties. In simpler terms, it cleans stuff.

Almost all drug stores and pharmacies sell hydrogen peroxide in liquid form in concentrations ranging from 3%-6%. Even at those lower concentrations, however, hydrogen peroxide is extremely corrosive. For both internal and external personal use, most healthcare professionals wouldn’t recommend using hydrogen peroxide in concentrations over 0.5% unless under their supervision or with their instruction.

Fun fact: you can send a man to the moon with that little brown bottle of H2O2! But don’t worry, we’re not recommending that you use rocket fuel as mouthwash. Hydrogen peroxide only works as a propellant at concentrations of 90% or more. Needless to say, that’s significantly higher than the commercially available 3% solutions sold in drug stores—and way higher than the 0.5% recommended concentration for household and personal use. A hydrogen peroxide mouthwash may give you an angelic smile but if you use it properly, it shouldn’t send you soaring into the heavens.

Is Hydrogen Peroxide Safe to Use as Mouthwash?

The short answer is, “Yes.” If used properly—and sparingly—H2O2 is safe and can improve oral and dental health and even help to fend off viral infections. That doesn’t mean that this alternative to traditional, over-the-counter mouthwashes doesn’t come without some risks.

  • Protect Your Enamel: Hydrogen peroxide is corrosive. While that means that it can whiten teeth, it also means that it can damage them. A 2007 study found, perhaps unsurprisingly, that higher concentrations of H2O2 did increasing amounts of damage to teeth while in-vitro. However, higher concentrations weren’t necessary to do significant damage. The longer the exposure—regardless of the strength of the concentration—the more damage there was. If you’re going to be using a hydrogen peroxide mouthwash, keep the rinsing limited to 30 seconds.
  • Spit it Out: Another name for hydrogen peroxide is oxygenated water. If that sounds like a marketing gimmick… that’s because it kind of is. Oxygenated water can also refer to a consumer water product aimed mostly at athletes. While the refreshing beverage product is safe for consumption, hydrogen peroxide is absolutely not. If you’re using it as a mouth rinse, be sure to spit it out. If ingested, it can cause damage to the digestive tract, nausea, and vomiting. And those are the milder side effects.
  • Black Hairy Tongue: It sounds worse than it is. Black hairy tongue describes a condition where your tongue looks, well, black and hairy. It is a temporary condition that occurs when the little bumps on your tongue (circumvallate papillae) turn black. Though there are several potential causes of black hairy tongue such as dry mouth and smoking, oxidizing agents can also cause the condition. If this happens to you, there’s no need to panic but you may want to consult your dentist about potential remedies.

Of course, it’s not all black tongues and rocket fuel. Hydrogen peroxide does also offer some benefits as a mouthwash.

  • Fight Off Infections: The antiviral and antimicrobial properties of hydrogen peroxide make it a great candidate for fighting off infections. If you have a bacterial or viral infection in your throat—yes, even including COVID—hydrogen peroxide can reduce the amount of infection and provide temporary relief from symptoms such as sore throat and coughs caused by hardened mucous.
  • Keeping Your Gums Clean: A 2017 report found that rocket fuel hydrogen peroxide was effective at improving dental and oral health by reducing the number of harmful bacteria in the mouth. Specifically, the report found a drop in Porphyromonas gingivalis—a bacteria known to cause gum disease. Further, most dentists recognize that hydrogen peroxide can provide temporary relief from the symptoms of gingivitis and help to heal bleeding gums and canker sores.

Note that most dentists do not believe that using hydrogen peroxide as a mouthwash can noticeably whiten teeth. However, it can reduce gum inflammation and relieve the symptoms of gingivitis.

How to Use Hydrogen Peroxide as Mouthwash

Making a safe and effective hydrogen peroxide mouthwash at home is pretty simple. If you have a 3% solution, you’ll want to dilute it by combining 1 part of hydrogen peroxide with at least 2 parts of water. Rinse your mouth with the diluted solution as you normally would for not more than 30 seconds. Be sure not to swallow any of the solution and rinse your mouth out with plain water after if you feel the need.

Just like with regular mouthwash, you may experience a temporary burning sensation that eases quickly. However, if the burning sensation is intense or worsens, spit out the solution immediately, rinse your mouth out with water and contact your dentist.

Alternative Mouthwashes

A diluted hydrogen peroxide solution isn’t the only type of mouthwash that you can improvise at home.

  • Salt Water: Saltwater rinses balance your mouth’s pH level, can provide similar relief from the symptoms of gum disease, and reduce the number of harmful bacteria in your mouth. Furthermore, saltwater won’t have the same corrosive effect on your teeth’s enamel as hydrogen peroxide would. Not to mention, accidentally swallowing some saltwater isn’t a cause for alarm—but you should still spit it out.
  • Baking Soda: Mixing half of a teaspoon of baking soda into a full glass of water is another great homemade mouthwash that can help combat bad breath.

Your Dentist Knows the Best Mouthwash for You

If you find yourself with an empty bottle of mouthwash, you can still complete your oral routine. Whether you opt for a hydrogen peroxide mouthwash, a saltwater rinse, or a baking soda and water blend, there are plenty of DIY mouthwashes you can make at home. Even so, you’ll want to make the trip to the pharmacy or drug store at some point as most dentists wouldn’t recommend prolonged use of improvised mouthwashes except in rare cases.

Check out our list of locations and book your next appointment with Dawson Dental today and let’s talk about finding you the best mouthwash for your smile.