Teeth whitening has become more popular in recent years, however, treatments can be pricey — whether done at the dentist’s office or at home.
Hydrogen peroxide, a natural form of bleach, is touted as a DIY whitening alternative, but is it safe? In this article, we’re analyzing hydrogen peroxide teeth whitening to see how effective it really is, and how to use it safely.
Hydrogen peroxide is an effective bleaching agent that can increase the whiteness of your teeth by up to 20 shades.
The use of at-home treatment can have adverse effects such as irritation and chemical burns, particularly if you use them every day.
Increased tooth sensitivity is common yet temporary, usually clearing up within a day.
You can use hydrogen peroxide as a rinse or paste if you cannot access commercial treatment, but homemade strips are not recommended.
Some alternative remedies, such as salt and vinegar, activated charcoal, and oil pulling may whiten tooth enamel or reduce plaque deposits.
Hydrogen peroxide is a type of bleach that turns substances white or colorless–it’s often used in cleaning products and as a method of bleaching hair.
When used correctly, peroxide does not remove proteins, minerals or other substances from teeth, meaning it does not remove the enamel.
Hydrogen peroxide has been shown to increase the whiteness of teeth by almost 20 shades . In fact, a study comparing several commercially available brands found that toothpaste with a hydrogen peroxide solution as the active ingredient was the most effective long-term whitening treatment.
After four weeks of continuous use, the tooth surface was an average of nine shades brighter in the peroxide group, just beating microbeads .
Learn more about the best teeth whiteners here.
DIY teeth whitening with hydrogen peroxide is relatively safe, but only if you’re very careful to use less than 3% hydrogen peroxide concentration. That’s easier said than done, it’s better to buy products that have been lab-tested. Here’s our quick overview of cheap and effective teeth whitening products on the market.
Visiting a dental clinic for professional teeth whitening can cost you hundreds of dollars. As a result, TikTok users are going viral with a new budget tooth whitening hack. The hack involves rubbing a 3% hydrogen peroxide solution on your teeth using cotton buds.
The solution is left to work for 30-60 seconds, with some TikTok users claiming they use this hack on a daily basis, which might be unsafe.
Although 3% hydrogen peroxide is within safe limits, this hack is highly discouraged by dentists. When used incorrectly, hydrogen peroxide can damage enamel and irritate your gums and other tissues in your mouth.
Tooth sensitivity is another common side effect of peroxide use, though this usually clears up in 24 hours, daily use can mean your teeth have no time to recover and the irritation may become permanent.
How long it takes to notice a tooth whitening effect varies by the severity of your current discoloration and the products used.
You may even start to notice a difference after one day of using hydrogen peroxide teeth whitening products. However, for best results, a treatment period of four weeks is recommended .
Hydrogen peroxide is a natural bleaching agent that can effectively whiten your teeth within four weeks, but avoid overtreatment and homemade products with variable ingredient concentrations.
In-office tooth whitening treatment commonly involves the application of hydrogen peroxide products with higher concentrations than the 3% level safe for general use. Your treatment may use a light-activated system too, where a light shines on your teeth to speed up and improve the process of bleaching your teeth .
Some dentists provide “supervised” treatments that you take home and complete yourself. Here, a whitening gel is placed in custom-made trays. This is intended to prevent inflamed gums, as the gel does not come into contact with anything but your teeth. These treatments use an average concentration of 10-38% carbamide peroxide .
Carbamide peroxide is more stable than hydrogen peroxide, extending the shelf life of teeth whitening products’ efficacy. Once it comes into contact with water, it breaks down into hydrogen peroxide and urea . This extra stability is important, as the FDA has previously issued recalls over teeth whiteners that destabilize and liquefy. However, hydrogen peroxide should be kept away from heat, as high temperatures could cause an explosive reaction.
There are several homemade hydrogen peroxide teeth whitening methods, some safer than others.
Making your own hydrogen peroxide mouthwash is an effective way to cover all of your teeth, and ensure that no trace of the peroxide overstays its welcome and causes irritation or damage.
To use peroxide as a rinse, mix food-grade, store-bought hydrogen peroxide with an equal amount of water. Thoroughly wash your mouth with the mixture for 30-60 seconds before spitting it out, avoid swallowing the solution.
If the mixture causes you any pain or other irritation, spit it out immediately and rinse your mouth thoroughly with clean water.
You can also make a hydrogen peroxide paste with baking soda. Using a few teaspoons of baking soda, slowly stir in a small amount of hydrogen peroxide until you have a thick paste. This should no longer be gritty, but still be thick enough that you can apply it to the surface of your teeth.
Brush the paste onto your teeth with a toothbrush for no more than two minutes. Slowly coat your teeth with gentle, circular movements. Afterward, thoroughly rinse it off with water, ensuring that all of the paste has been removed from your mouth.
Check out the best whitening toothpaste brands, with and without hydrogen peroxide.
Some people use the above peroxide paste as homemade whitening strips. These are made by coating foil, coffee filter paper or another material with the paste, and holding it to the teeth for longer periods. This is more likely to cause negative side effects than other methods, such as irritation to the gums and increased tooth sensitivity.
The American Dental Association advises against homemade teeth whitening solutions, in particular whitening strips. Their variable concentrations of hydrogen peroxide and lack of research surrounding some recipes make it difficult to predict what effects you will see, including whether their benefits outweigh any risks.
Read more about the best teeth whitening strips.
Rinsing your mouth with hydrogen peroxide solutions, brushing on paste or holding the paste to your teeth for a longer period are three common ways to use peroxide as an at-home teeth whitener.
With correct use, hydrogen peroxide solutions are safe to put on your teeth. Concentration and contact time of hydrogen or carbamide peroxide, as well as any light use, affect your chance of side effects and their severity. Overall, it’s best to use either a less concentrated hydrogen peroxide solution or a shorter treatment time.
The ADA advises caution when using hydrogen peroxide as a homemade teeth whitening solution. Over-the-counter whitening treatments can be vetted and carry the ADA Seal of Acceptance, meaning they fit a set of safety and efficacy standards. If you choose to use whitening kits or products at home, it is best to select one with this seal.
It is essential that you do not use a hydrogen peroxide solution for any longer than two minutes at a time. Case reports of chemical burns after using 3% hydrogen peroxide for teeth whitening have been recorded, affecting the gums, tongue, and tissue underneath the tongue.
In the worst-case scenarios, the use of hydrogen peroxide at concentrations over 3% can even cause tissue necrosis, in other words, tissue death. This is a potential risk when you use it incorrectly, which is why following product indications and choosing brands with an ADA Seal are important steps.
Treating chemical burns after incorrect use of teeth whitening solutions, or those with an excessive hydrogen peroxide concentration, involves reducing inflammation and cleaning your mouth. Stringent rinsing of your mouth and local pain relief or corticosteroid drugs are common ways to relieve adverse effects of peroxide for teeth whitening .
When used according to their directions, whitening products with hydrogen peroxide and the ADA Seal of Approval are safe and effective.
The main side effects of teeth whitening products that contain hydrogen peroxide are increased tooth sensitivity and mouth irritation. They are generally mild and short-lived and are more likely when using hydrogen peroxide at higher concentrations .
Some side effects of using peroxide for teeth whitening come from its ability to increase tooth sensitivity. You may find eating hot or cold foods to be more uncomfortable, especially if you already have sensitive teeth. Overuse of home whitening products raises your risk of long-term hypersensitivity to heat.
If you have mild tooth decay, such as exposed root surfaces or a cracked tooth, the delicate dentin underneath may be particularly susceptible to worsened teeth sensitivity.
Eroded enamel can lead to tooth discoloration by partially exposing the dentin. If you are relying on at-home treatments alone, you may miss this as an underlying cause and feel that your teeth are simply sensitive.
In as much as the side effects of dilute hydrogen peroxide may be mild, anything over 3% concentration is harmful and could even lead to severe gum disease.
Beyond hydrogen peroxide, there are several other alternative DIY whitening treatments available:
Let’s look at how they work, how well they work, and any side effects you can expect.
Baking soda, often alongside pureed acidic fruits such as strawberries or green apples, is an unusual-sounding method of whitening teeth. The belief that this is an effective way to whiten your teeth comes from their malic acid content. A study comparing a baking soda and strawberry mixture to commercial whitening products found it to be the least effective treatment.
It is not recommended that you try strawberry puree for whitening your teeth. The acid and sugar contents stain human tooth enamel over time with excess exposure and insufficient cleaning .
Vinegar is an accessible ingredient with a number of uses, including natural cleaning products. Another study comparing baking soda and vinegar, or salt and vinegar, against hydrogen peroxide found that the salt and vinegar combination was similarly effective to peroxide. Treatment time was five minutes per day .
Charcoal is an abrasive ingredient that scrubs teeth stains off the enamel surface. In one population study, those brushing their teeth with a traditional blend of charcoal and salt had a distinct type of abrasion pattern .
On the other hand, research comparing several commercially available brands was more positive. While there was no mean change in whiteness after one use, there was an average increase of 7.4 degrees after four weeks of daily use 
One study showed the effectiveness of activated charcoal for teeth whitening, as it increased the ASGU score from 0.0 to 7.40
Oil pulling is a traditional Ayurvedic method of maintaining oral health, which aims to remove impurities from the mouth and body as a whole. This involves taking a small amount of oil and swishing it in your mouth for 10-20 minutes, before spitting it out (do not swallow this).
In a study involving dental students, volunteers were assigned either the oil or a placebo, both of which were meant to be swished in the mouth every day for one week, for 10 minutes a day. Although coconut oil is not directly effective in whitening teeth, it can remove plaque from tooth enamel after one week of use .
Finally, dietary changes may help to maintain the benefits of tooth whitening treatments. Coffee, wine, and cigarettes all contribute to stains directly, while excess sugar can indirectly form stains. When sugars interact with proteins, a non-enzymatic browning reaction may result, which is also a source of oxidative stress .
Solutions of salt and vinegar, and activated charcoal toothpastes, may help to whiten teeth. Additionally, oil pulling and removing sources of stains from your diet can prevent future discoloration and other oral health issues.
Let’s answer some of the most common questions regarding hydrogen peroxide.
Hydrogen peroxide is a common way to whiten teeth through bleaching, as the oxidative free radicals it generates strips stains of their color.
Dentists commonly use concentrations of 6% hydrogen peroxide, or 10% carbamide peroxide in effective whitening treatments. These have faster effects than more dilute solutions but are not so high as to cause teeth and gum damage.
Commercial whitening products generally contain hydrogen peroxide concentrations between 5 to 10%, meaning 6% is within the safe limit.
If you decide on whitening your teeth with hydrogen peroxide at home and only have a 35% solution, or choose this concentration for potential higher purity, you must dilute it. Mix the concentration with 10-20 times the amount of water, so it is diluted to less than 3%.
An example of commercially available peroxide strips is Crest 3D White. Keep in mind that this is the riskiest method of teeth whitening with hydrogen peroxide if you wear them for too long.
Hydrogen peroxide is a safe method of teeth whitening when performed correctly. It is best to use products available from a dentist or those that have an ADA Seal of Approval, in order to avoid adverse effects such as chemical burns. If you do use home remedies, try a lower concentration and avoid using it every day.