The short answer is YES, but it does not apply to ALL medicines.
Why Do Drugs Have an Expiration Date?
According to the Harvard Health Letter, an expiration date is a legal requirement that has been imposed by the Food and Drug Administration since 1979. It is meant to be the date until when “the manufacturer can still guarantee the full potency and safety of the drug.” However, research shows that 90% of more than 100 types of medication, both over-the-counter and prescription, are fine to use even 15 years after they have supposedly expired.
You can actually ignore the expiration date of many different drugs for up to many years! According to a report published in the Journal of the American Medical Association (JAMA), certain kinds of medication may retain much of their potency for as many as 40 years.