Do prescription drugs actually expire on their expiration date?

The date on the bottle is typically just one or two years after manufacture, and simply shows how long the maker tested the drug’s stability by exposing it to extreme temperatures, humidity and light.

Numerous studies on expired but properly stored drugs, mostly pills, have found them fully potent or close to fully potent, years after that date.

But experts say not to use expired liquid medicines, insulin and other injected drugs that must be refrigerated, as they can break down faster than pills, especially if they aren’t kept cold.

That goes for all drugs not properly stored, as medicines kept in areas with high humidity or fluctuating temperatures, such as a bathroom cabinet, or left in direct light degrade faster and can lose potency.

Both the U.S Food and Drug Administration and Health Canada generally advise against using expired medications.