Yes. Whitening strips can expire. Most strips use a peroxide-based gel that gradually loses strength, while the adhesive may dry out or stop holding the strip evenly against the teeth. An expired strip is therefore less likely to produce a predictable result.
How to find the expiration date
Check the outside of the box and each sealed foil packet for an expiration or “use by” date. Packaging varies by brand, so follow the manufacturer’s printed instructions. If the date is missing or unreadable, contact the manufacturer rather than guessing how old the product is.
When should whitening strips be discarded?
Replace the strips if the package is past its printed date or if you notice any of the following:
- The individual packet is torn, open or leaking.
- The gel looks dry, discolored or uneven.
- The strip no longer adheres properly to the teeth.
- The box was stored in a hot car, direct sunlight or a damp location.
Do not compensate for an old product by wearing it longer, doubling the strips or using more treatments than the label recommends. Those changes can increase tooth sensitivity and gum irritation without giving a better result.
How to store whitening strips
Keep the strips sealed in their original packaging in a cool, dry place away from sunlight and heat. A bathroom cabinet may be convenient, but repeated humidity can be hard on packaging. Avoid leaving the product in a vehicle or near a window.
Is it safe to use an expired strip?
The safest, most predictable choice is to use an unopened, in-date product exactly as directed. This is especially important if you already have sensitive teeth, gum disease, cavities, exposed roots or dental restorations. Whitening gel does not lighten crowns, veneers or tooth-colored fillings, which can create an uneven appearance.
When to ask a dentist about whitening
See a dentist before whitening if one tooth has become noticeably darker, you have pain or lingering sensitivity, or the discoloration does not respond to an over-the-counter product. A dental exam can identify decay, a leaking restoration or a problem inside the tooth that whitening strips cannot treat.
For more guidance, read our tips for using whitening strips, compare professional teeth-whitening options, or learn about ZOOM! whitening in Tucson. If it has been a while since your last visit, a dental checkup is a good place to start.