Is It Safe To Use Hydrogen Peroxide Products To Whiten Your Teeth?

You may have wondered about all teeth whitening or "bleaching" products on the market, many of which contain hydrogen peroxide. After all, who doesn't want a bright, white smile? Are these products safe? And are they effective? Dentists and other experts weigh in.

How Does Hydrogen Peroxide Make Your Teeth Whiter?

"Hydrogen peroxide has actually been used in teeth bleaching products and oral care products like toothpaste and mouthwash for decades," dentist and Waterpik spokesperson Chris Strandburg, DDS, told Health.

Hydrogen peroxide is an acidic chemical compound with the formula H₂O₂, and in its pure form, it's a very pale blue liquid. In addition to oral care products, it's often used as a household cleaner, bleaching agent, or antiseptic. It's a powerful oxidizer in high concentrations and can be corrosive to the eyes, skin, and respiratory system. For this reason, hydrogen peroxide needs to be used with caution on people and animals.

Hydrogen peroxide's strong bleaching properties make it a common ingredient in teeth-whitening products. "Hydrogen peroxide brightens and whitens the teeth via a chemical process, by breaking down the stains from polymers into monomers via an oxidation process," UK dentist Dr. Lisa Creaven, co-founder of Spotlight Oral Care, told Health. "In teeth whitening products, it works to dissolve stains, so teeth are gradually and safely whitened without damaging tooth health."

Because it's so strong, it's typically diluted with a whitening product, such as baking soda, to prevent damage to the enamel and gums.

How Safe Is It?

As an ingredient in commercial whitening products, which are regulated and controlled, hydrogen peroxide is completely safe. You will find it in toothpaste and mouthwashes, as well as a variety of whitening products, including strips, pens, and gels that are squeezed into rubber trays that wrap around the teeth. These products all allow hydrogen peroxide to come in close contact with the tooth surface, where it breaks down stains and brightens the overall shade of the tooth.

"Hydrogen peroxide has a long track record of safety for bleaching teeth without significantly affecting the strength of tooth enamel," Dr. Strandburg said. However, it is possible to overdo it and damage your teeth and gums over time.

Over-the-counter teeth whitening products typically contain hydrogen peroxide concentrations of 3 to 20 percent. The treatments you can get at the dentist's office can be even more concentrated.

Most toothpastes and mouthwashes contain a lower amount, which makes them weaker and, therefore, safer for long-term use. In these products, hydrogen peroxide also helps kill bacteria that contribute to gum disease, which improves gum health.

Whitening strips or gels can irritate your gums or make your teeth sensitive in some cases, but limiting applications or giving yourself rest periods between sessions can help you avoid these issues.

"Prolonged bleaching with these high concentrations of hydrogen peroxide, especially when used multiple days in a row, can lead to highly irritated gums and sensitive teeth," Dr. Strandburg warned. "Gum irritation can get severe if more bleaching is done when the gums are already irritated. Tooth sensitivity is usually temporary (24 hours or so), but significant bleaching can increase tooth sensitivity permanently with long-term use."

Whiten With Caution

Dr. Strandburg recommended limiting your first treatment to between seven and 14 sessions. To stay on the safe side, you should give your teeth and gums a day's rest between sessions. You should also avoid doing more than 20 bleaching sessions per year, which can be risky to your teeth's enamel. Sticking with this advice gives most people "a nice boost to their tooth brightness with little to no lasting negative effects," said Dr. Strandburg.

Also, avoid doing a course of any whitening product with hydrogen peroxide more than once or twice per year, said orthodontist Heather Kunen, DDS, MS, co-founder of Beam Street. "Once you have achieved the level of whitening you want (over the course of three to 10 days), wait at least another six to 12 months before whitening again," Dr. Kunen told Health.

You should also use care if you are thinking about creating your own hydrogen peroxide whitening mixture at home."The bleaching agent can badly burn your gums and damage enamel if the concentration is too strong," Dr. Kunen warned. To make your own solution, Dr. Kunen recommended diluting to at least a 1:1 ratio of water to hydrogen peroxide, but always check with your dentist first.

What About Alternative Bleaching Ingredients?

Hydrogen peroxide isn't the only teeth-whitening ingredient out there.

Carbamide peroxide is another very common whitening agent in over-the-counter products. It's a combination of hydrogen peroxide and carbamide and is very similar, according to the American Dental Association—it just works a little more slowly but has a longer shelf life.

Baking soda isn't a true bleaching agent, Dr. Kunen said, but it helps to lift stains from teeth to give them a nice sparkle.

Pthalimidoperoxycaproic acid (PAP) is another bleaching alternative. "Other whitening brands are starting to stray from traditional peroxides and use new formulas that are less harsh, such as pthalimidoperoxycaproic acid (PAP)," Dr. Kunen added. "PAP is far less harsh on the enamel and gum tissues than hydrogen peroxide, so this formula may become more popular for other brands in the near future."

Charcoal is another option you may have heard about but beware. According to research from the Journal of the American Dental Association (JADA), charcoal products have the least evidence of both safety and efficacy. Dr. Creaven also advised against this one.

"Research shows that toothpaste and teeth whitening products that contain abrasives such as charcoal can cause irreversible damage to the tooth surface," Dr. Creaven said. "Charcoal-based toothpaste work by mechanically removing the outermost layer of the enamel surface, which physically and permanently removes tooth structure. When these products are used over a long period of time, they can make the top surface of the teeth rough and dull, leading to a more yellow appearance overall."

No matter which whitening method you choose, it's always best to talk with your dentist first and make sure your teeth and gums are in good shape. "Dentists have the health of your mouth as their first priority so making them part of your routine will ensure excellent oral health throughout your life," Dr. Creaven said.

This article was medically reviewed by Steffini Stalos, DO, who is board-certified in Pathology and Lab Medicine, on July 5, 2022.