Using hydrogen peroxide in a rinse or a paste may help whiten your teeth. But a high concentration or long-term use may cause damage to your teeth.

Hydrogen peroxide is a chemical compound sold in liquid form. It has many household, industrial, and medical uses. For instance, it can be used to bleach hair, disinfect contact lenses, preserve foods, and treat warts.

It’s also one of the most common ingredients in teeth-whitening products, such as mouthwashes, toothpastes, and whitening strips.

Although research suggests that it can help whiten teeth, prolonged use could cause several side effects.

Keep reading to learn more about the possible benefits and risks of using hydrogen peroxide for your teeth and how to use it safely.

Hydrogen peroxide acts as a bleaching agent when it’s applied to your teeth. It can help remove stains caused by foods and dyes and improve the lightness of your teeth due to its effects on the tooth’s enamel (outer coating).

Most hydrogen peroxide bottles you can buy at a store are diluted to around 3% to 9%. This may be lower than the amount available in commercial whitening treatments, but this doesn’t mean it can’t help whiten your teeth.

A 2023 study found that using an at-home solution containing 6% hydrogen peroxide 30 minutes daily for 2 weeks was more effective at whitening teeth than:

  • using an in-office 35% solution for 10 minutes daily for 3 days
  • using an in-office 40% solution for 20 minutes daily for 3 days

Although it took longer to achieve these results, experts advise against using hydrogen peroxide products above 6% concentration for dental treatments.

Concentrations that are too strong can damage the enamel and increase the risk of side effects.

Several studies suggest that using hydrogen peroxide — whether in a commercial product or at home — can cause damage to your teeth.

The most common side effect is temporary tooth sensitivity, which affects up to 80% of people who use hydrogen peroxide on their teeth. After a peroxide treatment, consuming hot or cold foods or liquids may be unpleasant.

When used for long periods or in high concentrations, hydrogen peroxide can stripminerals (demineralization) and proteins (deproteinization) from your teeth. This may allow oxygen compounds to reach the nerves of teeth in your gums, causing temporary inflammation.

In some cases, gum inflammation can lead to secondary issues like infection, which may require medical treatment.

The risk of damage may increase when you:

  • use a hydrogen peroxide solution higher than 6%
  • leave the hydrogen peroxide in contact with your teeth for a long time (longer than 1 minute if swishing or 2 minutes if brushing as a paste)
  • apply the hydrogen peroxide to your teeth more than once daily

It’s important not to use hydrogen peroxide products with a concentration higher than 9%. Skin or eye contact with products containing higher concentrations may burn, sting, and cause dryness.

Ingesting hydrogen peroxide over 30% may also cause life threatening complications, such as death.

Talk with a dentist before applying hydrogen peroxide to your teeth to determine which teeth whitening strategy and application schedule is best for you.

There are two ways: swishing it around your mouth, or mixing it with baking soda and setting it on your teeth as a paste before rinsing.

Using hydrogen peroxide as a rinse

  1. Mix equal amounts of hydrogen peroxide with water, such as 1/2 cup to 1/2 cup.
  2. Swish this mixture around your mouth for 30 to 60 seconds.
  3. Spit out the solution.

If the solution hurts your teeth or mouth, spit it out and rinse your mouth with water immediately. Try not to swallow any of the mixture, as this may cause gastrointestinal discomfort.

Using hydrogen peroxide in a paste

  1. Mix a few teaspoons of baking soda in a dish with a small amount of peroxide.
  2. Start to mix the soda and peroxide with a clean spoon.
  3. Keep adding a little bit more peroxide until you get a thick — but not gritty — paste.
  4. Use a toothbrush to apply the paste to your teeth using small and gentle circular motions. Brush for no longer than 2 minutes.
  5. Thoroughly rinse off the paste by swishing water around your mouth.

Make sure you remove all of the paste before moving on with your day.

Can you apply hydrogen peroxide directly to your teeth?

No, it’s important to mix hydrogen peroxide with water or baking soda to dilute the solution.

Proper dental hygiene is key to preventing bacteria and plaque buildup that causes tooth discoloration. This includes brushing your teeth twice daily with toothpaste and regularly flossing.

According to a 2023 and 2022 review of studies, the following natural ingredients may be safer than and as effective as hydrogen peroxide for whitening teeth:

You can also take preventive measures to minimize teeth staining, including quitting smoking (if you smoke) and limiting your intake of certain foods, such as coffee, tea, red wine, and candy.

Hydrogen peroxide is an inexpensive household product that you may already have on hand.

When used carefully, it could be an effective way to whiten your teeth. But if used incorrectly — in concentrations that are too high or if used too often — it can cause serious and sometimes expensive tooth damage.

If you choose to whiten your teeth with hydrogen peroxide, do so cautiously. Consider speaking with a dentist, who can advise you on the safest way to do so.