While many people believe it's safe to take medications well past their expiration, taking expired medications can be risky and is generally not recommended. Once past the expiration date, drugs may not be as potent (strong or effective) or may alter composition, meaning the ingredients break down and change over time. Factors Influencing Medication PotencyThere is evidence that many drugs retain 90% of their potency for at least five years after their expiration date. A Quick ReviewAn expiration date reflects how long the manufacturer guarantees the safety and efficacy of the drug. While there is some evidence that drugs retain their potency for years after their expiration date, the FDA states that taking expired drugs may be risky.