When a drug is manufactured, it keeps its potency, or strength, for only a certain time. That time is different for each drug. After that time, the drug’s chemical composition starts to change and the drug weakens or deteriorates. It can no longer have the intended health effect. The change is slow, but certain. The drug’s expiration date is the time when its chemical composition will be too weak to help. Most of the chemical changes in a drug are not dangerous in themselves. But some are. That’s another reason why using a drug before its expiration date is crucial. These.
