Have you ever wondered - do whitening strips expire? If you’ve stumbled upon an old box of whitening strips in your bathroom closet or drawer, you may be tempted to put them to use to save a bit of money. But is it truly safe or effective to use whitening strips past their expiration date?
In this comprehensive guide, we’ll dig into all the nitty-gritty details about whitening strips, including how they work, what happens when they expire, whether you can still use them, proper storage guidelines, and alternative options.
Before we dive into whether or not whitening strips expire and how to use them properly, let’s start with the basics and understand exactly what they are and how they work to whiten your teeth.
Whitening strips consist of thin, flexible pieces of plastic that have one side coated with a peroxide-based whitening gel. This gel is the active ingredient that penetrates the tooth enamel and works to break down and remove stains built up on the teeth from food, drinks, smoking, medication use, or simply age.
The most common active ingredients you’ll find in whitening strip gels are:
● Hydrogen peroxide - This is a powerful bleaching agent that serves as a strong oxidizer to lift and dissolve stains in the teeth, leaving them whiter.
Carbamide peroxide - This agent breaks down into hydrogen peroxide and urea. The hydrogen peroxide provides the whitening action, while the urea helps activate and stabilize it.
When you apply whitening strips to your teeth, the peroxide-based gel interacts with your tooth enamel and gets into the tiny pores and crevices. This allows the active ingredient to penetrate deep into the teeth and reach the discolored molecules underneath the enamel surface.
The peroxide acts as an oxidizing agent to break apart the complex organic molecules that cause yellowing and discoloration. This process lightens the natural color of the dentin beneath, leaving your teeth looking brighter and whiter!
Now that we understand how whitening strips work to remove stains and whiten teeth let’s get into the actual expiration and shelf life of these products.
The short answer is yes - whitening strips do have an expiration date and can expire over time. Most brands of whitening strips have a shelf life of 1-2 years from the date they were manufactured.
You’ll be able to find the expiration date printed on the outside packaging of your whitening strips. It might say something like “Best if Used By” or “Expiration Date” followed by a month and year. This is the manufacturer’s recommendation for how long the strips are designed to maintain their potency and effectiveness.
So why do whitening strips expire, and what happens when they are used past their expiration date?
As the strips age beyond their expiration date, the concentration and integrity of the active peroxide-based ingredients start to degrade and become less potent. The oxidizing and stain-removing capabilities weaken over time.
Exposure to moisture, air, light, or fluctuating temperatures can accelerate the breakdown of the gel’s ingredients as well. The longer the strips are stored past their expiration date, the less effective they become at brightening your smile.
● Weakened bleaching power and lighter whitening effect
● Patchy or uneven whitening results
● Increased risk of tooth sensitivity or irritated gums
● Dry, cracked gel that doesn’t adequately adhere to teeth
● While some people may still decide to use expired whitening strips to finish up an old package, it’s important to understand they won’t work nearly as well as fresh, non-expired strips. We don’t recommend relying on old strips for an intense teeth whitening session before an important event. Stick to newer products for the best and safest results!
Okay, so it’s clear that whitening strips do expire eventually and won’t work as well past their expiration date. But can you still use them even if they are expired? What are the risks versus potential benefits?
The answer isn’t quite so black and white.
Technically, it is possible to use still whitening strips that have expired, especially if you only have a package or two on hand. However, we don’t generally recommend using expired whitening strips, as there are a few precautions and drawbacks to consider:
● As mentioned, the efficacy of the gel to whiten your teeth will be reduced, so you likely won’t see dramatic results. But some minor brightening might still occur.
● Sensitivity and irritation risks increase as the chemicals degrade and become harsher or less stable. Use a very light hand and stop immediately if you experience discomfort.
● The gel may dry out or not adhere well to teeth if the product is very old and dried up. Rehydrating with a damp cloth may help temporarily.
● Due to lower effectiveness, you’ll likely need to use more strips more frequently to see any noticeable whitening effect, which gets expensive.
● If you have no adverse reaction to the first strip, you’re probably fine to proceed with the rest of the package. But monitor yourself carefully for increased pain or gum irritation as you continue usage.
Overall, while not necessarily unsafe if you evaluate the condition of the gel and monitor for side effects, using expired whitening strips is not the ideal teeth whitening option. We suggest investing in a fresh package for the best and most comfortable results.
Now that we’ve covered whether whitening strips expire and what happens when they do let’s go over some tips on how to properly store your strips to help extend their shelf life as long as possible. Here are our top storage recommendations:
● Whenever possible, keep whitening strips in their original product packaging. This helps protect the gel from air and moisture exposure.
● If you’ve opened the package but have strips left over, tightly seal or roll up the opened section before placing it back in the box for storage.
● Store unused strips in a cool, dry place away from direct sunlight and heat sources like hot water pipes. The bathroom medicine cabinet is a good option.
● For multiple boxes, use a sealed plastic container or zipped plastic bag to keep strips organized and prevent moisture damage.
● Keep whitening strips separate from other medicines or chemicals that could react with the gel ingredients.
● Check expiration dates frequently and toss boxes that are more than 1-2 years old from the manufactured date, depending on the brand.
● Don’t freeze whitening strips, as this could negatively impact the formulation. Refrigeration is okay for very short-term storage.
Following these guidelines will help your whitening strips maintain their potency and effectiveness for as long as possible. Be diligent about proper storage and expiration dates to get the most value from your whitening strip investment.
If you open up your stash of whitening strips only to realize they are months past expiration, don’t fret! There are plenty of other effective teeth whitening options to explore rather than having to resort to uncertain, expired products.
Here are some of our top recommendations for whitening treatments to use instead of outdated strips:
For the fastest and most dramatic whitening results, you can’t beat professional in-office power whitening done by your dentist. They will use higher concentrations of whitening gels alongside special LED lights to accelerate stain removal. While more expensive than strips, it works quickly and effectively to brighten your smile for 1-3 years.
Dentists can also provide custom-fitted whitening trays designed just for your teeth so you can continue to whiten at home between office visits. This helps maintain professional whitening results.
Over-the-counter LED whitening kits that use blue light energy to enhance the effects of hydrogen peroxide gels are the next best option after professional whitening. The light activates the ingredients to work faster without sensitivity. The upfront costs are higher than strips, but you can reuse the kit.
With consistent use, LED kits gradually whiten over a couple of weeks and help maintain results when touched up periodically. Take care applying the gel evenly across all teeth.
For more natural-minded folks, activated charcoal powders and toothpaste are gentler alternatives. Charcoal is thought to absorb surface stains from the tooth enamel through a process called adsorption. Most charcoal pastes also contain mild abrasives to polish away discoloration gently.
Wet your toothbrush, dip in the charcoal powder, and brush for 2-3 minutes. Make sure to rinse your mouth thoroughly after as charcoal can be messy. You’ll need to use these products regularly over time to see gradual whitening.
Another easy option is whitening mouthwashes or rinses containing hydrogen peroxide that you swish around your teeth for 60 seconds daily. Most rinses use lower peroxide concentrations, so whitening occurs gradually over 4-6 weeks of consistent use.
Whitening rinses help remove surface stains and are great for quick touch-ups or occasional brightening between deeper whitening treatments. They tend to be affordable and easy to incorporate into your daily oral care routine.
After reviewing all the intricacies around whether whitening strips expire, proper use and storage, plus safer alternatives, what’s the overall verdict?
We don’t recommend relying on expired whitening strips as your main teeth whitening strategy. While technically, you may be able to complete an old package with minimal issues, the results will be underwhelming. Plus, there are risks of side effects like sensitivity or gum irritation.
Q: Do whitening strips lose effectiveness if left open?
A: Yes, when exposed to air and humidity, the whitening gel on strips can begin to dry out and lose potency if left open and unsealed for extended periods. Always re-seal opened strips.
Q: Can you rehydrate dried-out whitening strips?
A: You can briefly rehydrate dried strips by dampening them with water. But results are temporary. Dried-out gel often indicates an expired product that won’t whiten effectively.
Q: Why do my teeth become sensitive after using whitening strips?
A: Sensitivity is common when using peroxide-based whitening products. However, severe or prolonged pain can indicate irritation from expired strips with a changed formulation. Discontinue use.
Q: Is it safe to whiten teeth with strips while pregnant?
A: While generally safe, whitening is not recommended during pregnancy. Consult your dentist first, as pregnancy can make teeth more sensitive and prone to damage from whitening agents.
Q: Can children use whitening strips safely?
A: Whitening strips are not indicated for children under 18. Young teeth are still developing enamel and dentin and are at higher risk of sensitivity from harsh whitening chemicals.
