Expiration dates on medications: Why are they important?

content provided by mayoclinic.com

Expiration dates on medications: Why are they important?

Question

When a medication has an expiration date of 01/06, does it mean it expires on Jan. 1 or Jan. 31? What happens if I keep taking it after that date?

Lori
Washington

Answer

When the label shows only a month and a year, the implied expiration date is the last day of that month. So, a medication with an expiration date listed as 01/06 expires on Jan. 31, 2006.

It's important to always check the expiration on medications you take. The expiration date assures that the drug meets applicable standards of strength, quality and purity at the time of use. This date is only valid as long as the drug is in the original, unopened container and kept under storage conditions specified by the manufacturer. Exposure to certain environmental factors — such as humidity, temperature, light and air — can affect medications.

A medication taken after the expiration date may have changed in potency or even formed harmful material. Contamination with germs also can occur. The safest rule is to not use any medication beyond the expiration date.

Last Updated: 06/08/2005
© 1998-2014 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "Mayo Clinic Health Information," "Reliable information for a healthier life" and the triple-shield Mayo logo are trademarks of Mayo Foundation for Medical Education and Research.

Terms and conditions of use

 

Bookmark and Share   E-Mail Page   Printer Friendly Version