...90% of more than 100 drugs, both prescription and over-the-counter, were perfectly good to use even 15 years after the expiration date.

So the expiration date doesn’t really indicate a point at which the medication is no longer effective or has become unsafe to use. Medical authorities state expired drugs are safe to take, even those that expired years ago. A rare exception to this may be tetracycline, but the report on this is controversial among researchers. It’s true the effectiveness of a drug may decrease over time, but much of the original potency still remains even a decade after the expiration date. Excluding nitroglycerin, insulin, and liquid antibiotics, most medications are as long-lasting as the ones tested by the military. Placing a medication in a cool place, such as a refrigerator, will help a drug remain potent for many years.