Are whitening strips ok if expired?

May not work: If expired..Will not get results as you can with not expired.

Not harmful: But you may not get the results you are looking for. The active ingredient(s) may no longer be effective.

Less potent: You can still use expired whitening products... Still follow instructions, just not as potent or effective.

Possibly: Depends on how expired. After expiration date medications begin to loose potency, so strips will just be less effective. Best, most effective, whitening system is provided by your Dentist, with strips being used (as directed on package) to maintain the professional result.