Tooth whitening has become more popular in recent years as more products come onto the market. But many of these products can be quite expensive, leading people to look for cheaper remedies.

The most affordable way to whiten teeth at home (and the remedy supported by the most significant body of research) is the main ingredient from most tooth-whitening products: hydrogen peroxide.

What does the science say?

Here’s what you need to know: Most hydrogen peroxide bottles you can buy at a drug store or grocery store are diluted to around 3 percent. The amount of hydrogen peroxide in commercial whitening treatments varies and can be as much as 10 percent in some products.

But scientific studies suggest dilution is a good thing when it comes to using hydrogen peroxide for teeth whitening; concentrations that are too strong can damage the enamel, or outer coating, of your teeth.

In one study, scientists applied diluted hydrogen peroxide solutions of 10, 20, and 30 percent to human teeth that had been extracted for varying amounts of time. They found that higher concentration solutions caused more damage to teeth, as did keeping the teeth in contact with hydrogen peroxide for a longer amount of time. This suggests that low-concentration treatments of hydrogen peroxide, applied for shorter periods of time, have the least potential to damage your teeth.

According to another study, scientists found that a 5 percent hydrogen peroxide solution was just as effective as a 25 percent solution at whitening teeth. But to achieve the same level of whiteness, one would need to whiten teeth with the 5 percent solution 12 times to get the same level of whitening as one time with the 25 percent solution.

This means if you’re using short, low-concentration treatments, you’ll have to perform more treatments in order to achieve your desired whiteness.

How do you use hydrogen peroxide as a teeth whitener?

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 hydrogen peroxide with water, such as 1/2 cup to 1/2 cup.
  2. Swish this mixture around your mouth for about 30 seconds to 1 minute.
  3. Stop and spit out the solution if it’s hurting your mouth and try not to swallow any of the mixture.

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 together 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 circular motions for two minutes.
  5. Leave the paste on your teeth for a few minutes.
  6. Then, 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.

Are there any side effects?

Several studies suggest that using hydrogen peroxide — whether in a commercial product or at home — can cause damage to your teeth. The risk of damage increases when you:

  • use a very strong hydrogen peroxide solution
  • leave the hydrogen peroxide in contact with your teeth for a long time (longer than one minute if swishing or two minutes if brushing as a paste)
  • apply the hydrogen peroxide to your teeth too many times (more than once daily)

Consult your dentist before applying any hydrogen peroxide to your teeth to determine which strategy and application schedule makes the most sense for your situation.

Tooth sensitivity is perhaps the most common side effect of hydrogen peroxide use. You may find consuming hot or cold foods or liquids unpleasant after a peroxide treatment. Avoid doing so for as long as you experience pain.

This happens because peroxide can cause significant damage to the protective enamel of teeth if used too often or in too-high concentrations. More serious side effects of hydrogen peroxide whitening include inflammation of the teeth roots in the gums. This problem can lead to secondary issues, such as infection, which can be expensive to treat.

Should you use hydrogen peroxide on your teeth?

Hydrogen peroxide is an inexpensive household product you probably have on hand right now.

When used carefully, it can 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. If you have any concerns, see your dentist, who can give you advice on the best way to whiten for your dental health.

In the meantime, you can preserve your teeth’s whiteness and prevent further staining by avoiding foods and drinks that can stain your teeth.

This includes:

  • energy drinks
  • coffee
  • tea and red wine
  • carbonated beverages, which may make your teeth more prone to staining
  • candy
  • berries, including blackberries
  • blueberries
  • strawberries and raspberries
  • tomato-based sauces
  • citrus fruits

If you do choose to consume these foods and drinks, rinsing or brushing your teeth afterward can prevent staining.