PEOPLE’S PHARMACY: Why ‘use before’ and ‘expiration’ dates differ

Q: When I picked up a prescription from the pharmacy, the pharmacy label had a “use before” date of 09/04/10. The manufacturer’s label, under the pharmacy label, had an “expiration” date of Dec 2012. Why is this?

A: It is more convenient for the pharmacist to put a one-year computer-generated “use by” date on the prescription label than to hunt for the manufacturer’s specific expiration date. In some states, the pharmacist is legally required to display a one-year use-by date.

As you discovered, this does not represent a true expiration date. If you request this information when you submit your prescription, the pharmacist could take a little extra time and provide it for you.

Joe Graedon is a pharmacologist and Teresa Graedon is an expert in medical anthropology and nutrition. They can be reached at

One comment Add your comment


December 18th, 2009
8:56 pm

>>>I find your answer quite useful. I am though, more interested in labeling of expiration date for Generic drugs on the dispensing bottle by the pharmacist in NY state. Also may time I find different manufacturer’s generic equivalent of the same brand medicine mixed together with different shape and size in the same dispensing bottle. What’s your take on this and is there any law in NY state that would prohibit it. I hope you are able to help with your experience and knowledge.Thanks.