Teeth whitening strips: do they work and should you use them?

On this page you will learn:

Summary – use teeth whitening strips if:

  • don’t mind using the treatment every day for one to three weeks
  • want something that is simple to apply, but are prepared for something a little more involved than a powder or pen
  • want a relatively cheap solution

Teeth whitening strips - overview

Price: €20–€40

How to use: Fix strips to teeth, leave and remove

Number of treatments: Varies – most are 2 or 3-week treatments.

How often: Daily for 2–3 weeks

What are they?

Teeth whitening strips are gel strips that you push on to the front of your teeth and fold over to whiten the back of your teeth.

They come in pouches of two – one for top teeth, one for bottom teeth. They can be:

  • dissolvable
  • non-dissolvable

You need two strips for each treatment. So if a product says 40 strips, that means 20 treatments.

Dissolvable vs non-dissolvable:


  • you have to remove strips after a specified time
  • usually they are peroxide, but some non-peroxide available.
  • Normally take 30-60 mins to work.


  • Dissolves away so no need to remove
  • Non peroxide
  • Normally 5 – 15 mins to work
  • Sometimes comes with an “accelerator” that you apply before the strips.

Find out why peroxide vs non-peroxide matters here.

All strips come with instructions.

How do strips whiten teeth?

Strips are very simple—the gel on the strip has a whitening agent in it. When this makes contact with your teeth it bleaches any stains or discolouration.

What’s in the gel?

Non-dissolving strips

In most non-dissolving strips the important ingredient is hydrogen peroxide—this is the chemical that actually whitens the teeth and can be found in plenty of teeth whitening products.

Dentists also use hydrogen peroxide to whiten teeth as part of a dental hygiene routine.

You can also get peroxide-free non-dissolving strips.

Other ingredients will be included to ensure the strips stay moist, taste nice and stick to your teeth.

Here’s a quick example of what the ingredients in one product do.

Crest 3D White Luxe Professional Effects Whitestrips ingredients (taken from manufacturer’s website)

Ingredient: PVP| What it is: thickening agent

Helps the strip stay in place.

Ingredient: PEG-8| What it is: solvent

Helps the strip stay in place

Ingredient: Water| What it is: solvent

Helps dissolve the other ingredients

Ingredient: Hydrogen peroxide| what it is: bleaching agent

Whitens teeth

Ingredient: Acrylates copolymer| what it is: polymer

Helps the strip stay in place

Ingredient: Sodium hydroxide| what it is: pH adjuster

Helps balance the pH

Ingredient: Sodium saccharin| what it is: sweetener

Makes it taste nice

Ingredient: Glycerin| what it is: Solvent/humectant

Stops the strip from drying out

Ingredient: Carbomer| what it is: thickener

Helps the gel hold its form

Dissolving strips

Dissolving strips don’t contain hydrogen peroxide, but otherwise have similar ingredients to non-dissolving strips.

The active whitening ingredient in dissolving strips is usually sodium perborate, sodium bicarbonate, sodium tripolyphosphate or sodium hydroxide.

Some dissolving strips have activated charcoal in them.

How to use them – how often:

  • Strips should be left on between 5–30 minutes
  • Most strips should be used once a day for two to three weeks.
  • Some you should apply twice a day.

How to use – process:

Non-dissolving strips

Each box of strips will come with its own instructions but the basic process goes like this:

  1. Make sure your teeth are dry.
  2. Rip open the pouch and identify which strip is for your top teeth and which is for your bottom.
  3. Place the bottom strip on your bottom teeth. You may need to fold it over depending on the type of strip you have bought.
  4. Place the top strip on your top teeth. Again, you may need to fold it over.
  5. Leave the strip for the specified time.
  6. Remove the strips.

Here’s a quick YouTube video taking you through the steps:

https://www.youtube.com/watch?v=pRHpRWB6OP0  (32 seconds in)

Dissolving strips

  1. Moisten the teeth and gums or apply the accelerator that came with the strips.
  2. Place a strip on your top teeth, apply pressure and fold over.
  3. Place a strip on your bottom teeth, apply pressure and fold over.
  4. The strips will dissolve in 5–15 minutes, depending on the product.


Normally between €20 and €40.


  • Affordable
  • Good starting product
  • Effective

How effective are strips?

If used correctly and you complete the full course, whitening strips are an effective way to whiten your teeth.

Depending on the brand you use, you may see a noticeable difference in as little as a few days.

The effectiveness varies from person to person. For example, if you have heavily stained teeth or regularly drink red wine or coffee (or other drinks that badly stain teeth), your results may not be as pronounced as someone who doesn’t.

Dr Leslie Renne Townsend,

“According to the ADA, most whitening strips, both over-the-counter and those purchased from dentists, are generally effective and safe. However, results and any resultant complications may vary on a case-by-case basis.”


  • Can be uncomfortable
  • Can seem uneven at first
  • Can cause sensitivity

Strips can be uncomfortable. They won’t cause pain but having strips on your teeth for 30 minutes is hard to ignore. And sometimes the gel can get a little gloopy when removing the strip.

Results can be uneven depending on how snugly the strip fits. However, though this may look pronounced when you first remove a strip (or it has just dissolved) the patchiness tends to settle into a more even colour within a few hours.

If the gel gets onto your gums it can cause sensitivity.

Use teeth whitening strips if you:

Teeth whitening strips are often a good place to start if you haven’t tried whitening before, since they are easy to use and affordable.

You may want to try strips first before you move on to other alternatives.

The best teeth whitening strips—our pick:

Spotlight Teeth Whitening Strips

Spotlight Teeth White Strips

Whitening ingredient: hydrogen peroxide

Time left on teeth: 60 mins.

Time to work: two weeks

28 strips included (14 treatments)

Price: €44.95

Buy now


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