Updated on February 15, 2024
5 min read

Do Teeth Whitening Gels Work?

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Do Teeth Whitening Gels Work?

Yes, teeth whitening gels work well if they contain an active ingredient like hydrogen peroxide or carbamide peroxide.1,2,3

Hydrogen peroxide and carbamide peroxide penetrate the tooth enamel and break down molecules that create stains. Both types of gel produce similar whitening results.

Get your brightest smile with NewMouth's top teeth whitening picks for 2024.

What is Teeth Whitening Gel?

Teeth whitening gels usually contain an active peroxide-based ingredient that lightens tooth discoloration, removes surface stains, and brightens your smile.

You can find teeth whitening gel in many products, including:

However, it’s not recommended to use whitening gel on its own because the process can be messy. Using a pre-filled tray (or whitening strips) is the easiest and most effective way to whiten teeth at home. 

Side Effects of Whitening Gel

Teeth whitening gel can cause some side effects, including:

  • Tooth sensitivity ⁠— Tooth sensitivity is the most common side effect you might experience when using at-home tooth whitening gels. It’s generally mild and doesn’t increase your risk of oral health issues.
  • Gum irritation ⁠— More rarely, a whitening gel could irritate your gums.4,5
  • Enamel erosion ⁠— Overusing teeth whitening gels or leaving them on longer than recommended can cause your teeth to wear down, as well as other dental issues.5

Many teeth whitening products now contain added ingredients that can help decrease tooth sensitivity and discomfort. Amorphous calcium phosphate and potassium nitrate are two common ingredients that have been shown to reduce sensitive teeth.6

How Fast Do Teeth Whitening Gels Work?

The speed of results from tooth whitening gels varies based on the concentration used and whether the application is done at home or professionally in a dental office.

In-office professional whitening gel treatments work faster because they are formulated with a higher percentage of either hydrogen peroxide or carbamide peroxide. Your dentist may also use an LED light to speed up the results.

Overall, in-office professional whitening is associated with faster results and a higher degree of whitening compared to over-the-counter gels, according to some studies.1,3,5

You’ll typically see results of at-home whitening gels within days or weeks. You’ll need to use them more frequently to maintain brightness and avoid shade relapse. On the other hand, professional whitening only needs to be retouched every six months to a year.

How to Use Teeth Whitening Gel At Home 

Teeth whitening gels can be used in many different ways, including:

  • Applying gel directly to your teeth using a syringe
  • Placing pre-filled gel trays in your mouth
  • Using whitening strips, which will stick firmly to your teeth during treatment

Depending on the product, at-home whitening gels are typically left on for 10 to 30 minutes. Follow the product’s instructions and be careful not to swallow the gel.

After the time is up, gently remove the gel from your teeth using a cloth or soft toothbrush. Then rinse your mouth well. Do not eat or drink anything for 30 minutes after the whitening process.

Best At-Home Teeth Whitening Gels

Depending on your needs, budget, and level of discoloration, the best at-home products that use teeth whitening gel include:

Teeth Whitening Strips 

Most whitening strips are made of a flexible plastic substance coated with a thin layer of bleaching gel. This gel is typically made of hydrogen peroxide or carbamide peroxide. 

The strips are held in place by the plastic coating and gel. You’ll leave them on for about 30 minutes.

Teeth whitening strips typically cost between $20 and $50 for 14 or more treatments, making them one of the most affordable options.

LED Teeth Whitening Kits

LED whitening kits typically include trays pre-filled with teeth-whitening gel and a special light to speed up bleaching. LED lights can reduce treatment time and sensitivity by up to 53 percent compared to gel alone.7 

Although LED whitening kits can brighten your teeth quickly and effectively, they are more expensive and time-consuming, costing up to $200 per kit. 

Three of the best LED whitening kits available online are Snow, GLO, and Opalescence Teeth Whitening Kit. 

Whitening Pens

Teeth whitening pens are designed for on-the-go whitening. Simply twist the pen, brush the gel onto your teeth, and whiten your smile within a few minutes.

Is At-Home Teeth Whitening Gel Safe to Use?

Yes, at-home teeth whitening gels are safe if you follow the instructions.

The primary safety concern regarding teeth whitening products is the misconception that they contain bleach. Most over-the-counter whitening products include a bleaching gel, but this does not mean they contain actual bleach. 

The term ‘bleach’ describes the chemical process for stain removal (oxidation of the stain molecules on your teeth). 

Always talk to your dentist before using any over-the-counter tooth whitening product.

More Reading


Teeth whitening gels are an at-home tooth whitening method containing hydrogen or carbamide peroxide. The active ingredient in a tooth whitening gel breaks down the molecules of a stain.

Tooth whitening gels are safe and effective, though professional teeth whitening treatments will always work faster and last longer than their at-home counterparts. You can apply a tooth whitening gel at home using a syringe, pre-filled tray, LED teeth whitening kit, or strips.

Always talk to your dentist before using a tooth whitening product. Follow the instructions carefully, and don’t overuse the products to ensure your teeth’s safety. Possible side effects of tooth whitening gels include tooth sensitivity and gum irritation.

Last updated on February 15, 2024
8 Sources Cited
Last updated on February 15, 2024
All NewMouth content is medically reviewed and fact-checked by a licensed dentist or orthodontist to ensure the information is factual, current, and relevant.

We have strict sourcing guidelines and only cite from current scientific research, such as scholarly articles, dentistry textbooks, government agencies, and medical journals. This also includes information provided by the American Dental Association (ADA), the American Association of Orthodontics (AAO), and the American Academy of Pediatrics (AAP).
  1. Eimar et al. “Hydrogen Peroxide Whitens Teeth by Oxidizing the Organic Structure.” Journal of Dentistry, National Library of Medicine, 2012.
  2. Carey, C. “Tooth Whitening: What We Now Know.” Journal of Evidence-Based Dental Practice, National Library of Medicine, 2014.
  3. Basting et al. “Clinical Comparative Study of the Effectiveness of and Tooth Sensitivity to 10% and 20% Carbamide Peroxide Home-Use and 35% and 38% Hydrogen Peroxide In-Office Bleaching Materials Containing Desensitizing Agents.” Operative Dentistry, National Library of Medicine, 2012. 
  4. Cvikl et al. “Enamel Surface Changes After Exposure to Bleaching Gels Containing Carbamide Peroxide or Hydrogen Peroxide.” Operative Dentistry, Allen Press, 2016. 
  5. Fiorillo et al. “Dental Whitening Gels: Strengths and Weaknesses of an Increasingly Used Method.” Gels (Basel, Switzerland), National Library of Medicine, 2019.
  6. Nanjundasetty, J et al. “Efficacy of Desensitizing Agents on Postoperative Sensitivity Following an in-Office Vital Tooth Bleaching: A Randomized Controlled Clinical Trial.” Journal of Conservative Dentistry, National Library of Medicine, 2016.
  7. Bortolatto, J et al. “Effects of LED–Laser Hybrid Light on Bleaching Effectiveness and Tooth Sensitivity: a Randomized Clinical Study.” Laser Physics Letters, IOP Science, 2013.
  8. Naidu et al. “Over-the-Counter Tooth Whitening Agents: A Review of Literature.” Brazilian Dental Journal, National Library of Medicine, 2020.
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