Drug manufacturers are required to stamp an expiration date on their products. On over-the-counter (OTC) medicines, the expiration date is often printed on the label or carton under "EXP" (see photo) or stamped without ink into the bottom of a bottle, carton, or the crimp of a tube.
But what does the expiration date mean? Is a medicine still safe to take after its expiration date? Will it cause harm or just not work after its expiration date?
Neither fully explains what the expiration date means. Actually, it's the date up until which the drug manufacturer can guarantee that the medicine is fully potent and safe to take based on product testing. Expiration dates are typically conservative to make sure you get what you paid for—a fully potent and safe medicine.
According to the FDA, expired medical products can be less effective and pose a risk to the patient due to changes in chemical composition in the medication over time. Once the expiration date has passed, there is no guarantee that the medication is safe and effective. It is important to go through your medicine cabinet and discard expired medications. For proper disposal refer to Discarding Medicines Safely section.
Replace expired medications to be sure you are using the most up-to-date product with the most up-to-date instructions for use. Since you last purchased the product, new dosing instructions or warnings may be advised; the strength may have changed to reduce the risk of errors; a new dosing device may be available to help measure doses more accurately; the product may be packaged in a new container more child-resistant than an older version of the drug; and so on. So, clean out your medicine supplies regularly, and replace any medicines that are expired.
Lastly, keep medicine in a cool, dry place away from light, such as a dresser drawer, closet shelf, or kitchen cabinet. Storing medicine improperly — in a damp bathroom cabinet — can cause medicine to be less effective before reaching the expiration date.
If you choose to store medicine in a kitchen cabinet, make sure it is away from the sink and hot appliances, as the change in temperature and humidity may affect the medicine. If storing medicine in an area with a lot of foot traffic, consideration should be given to prevent children from easily accessing it, as to prevent accidental poisoning.
1) Drugs past their expiration date. The Medical Letter on Drugs and Therapeutics. October 8, 2002;44(1142):93-94.