Written by Calvin Bennet · Medically reviewed by Dr. Scott A. Puckett, DDS · Updated August 2026
Teeth whitening works by using peroxide-based gels to break down stains. Your options range from over-the-counter strips and toothpastes to dentist-supervised take-home trays and in-office treatments — differing mainly in peroxide strength, speed, how long results last, and cost. Whitening is generally safe when used as directed; sensitivity is the most common side effect.
How whitening works
Most whitening uses hydrogen peroxide or carbamide peroxide, which break down pigmented stain compounds in the enamel. Hydrogen peroxide works faster but is more likely to cause sensitivity; carbamide peroxide works more slowly with less sensitivity.
Your options
| Option | Peroxide strength | Speed / longevity | Typical cost* |
|---|---|---|---|
| In-office professional | Highest (~15–43%) | Fastest; ~1–3 years | ~$300–$1,000 |
| Dentist take-home trays | Medium (~10–16% carbamide) | Slower; ~1–3 years | ~$150–$600 |
| OTC strips / LED kits | Lower | Weeks; fades ~3–6 months | ~$20–$300 |
| Whitening toothpaste | Lowest (surface stains) | Gradual maintenance | ~$5–$15 |
Is teeth whitening safe?
Whitening is generally safe when used as directed. The most common side effect is temporary tooth sensitivity or gum irritation. Look for the ADA Seal of Acceptance, follow directions, and check with your dentist first — especially if you have sensitivity, gum disease, or dental work (whitening doesn’t change the color of crowns or fillings). The ADA suggests OTC strips contain no more than ~10% hydrogen peroxide or ~35% carbamide peroxide.
Which should you choose?
- Fastest, most dramatic + dentist oversight: in-office.
- Great results at lower cost: dentist take-home trays.
- Budget / mild staining: OTC strips with the ADA Seal.
- Maintenance only: whitening toothpaste.
Sources
Frequently Asked Questions
Is teeth whitening safe?
Yes, when used as directed; temporary tooth sensitivity is the most common side effect. Look for the ADA Seal and ask your dentist if you have concerns.
How long does teeth whitening last?
In-office and custom trays often last 1–3 years; over-the-counter strips typically fade in 3–6 months, depending on your habits.
Does whitening damage enamel?
Used as directed, whitening is not shown to damage enamel; overuse can increase sensitivity, so follow the instructions.
Will whitening work on crowns or fillings?
No — whitening only affects natural teeth, not dental work, which is worth planning around.
Related reading
Medical disclaimer: this article is for general education and is not a substitute for professional dental advice. Talk to your dentist about what’s right for you.