The topic of expired medications has been very popular recently! We have been answering many question about it and wrote a short article on it as well which can be seen here: 


​http://www.pharmacistanswers.com/fact-or-fiction--expired-drugs-are-harmful-to-use.html


There really is no good way to determine how long a drug is "good" for after the expiration date. You would need to do specific stability testing for each specific drug to see if it still potent. The drug manufacturer sets the expiration date based on a time period for which they know their drug will continue to meet FDA standards for purity and potency. After this date, there is no guarantee.


This question comes up often to pharmacists and it is really hard to give a precise answer. You will almost never get advice from a health care professional stating that it is OK to take expired medication as there are too many legal issues surrounding such advice.


The good news is that almost no drug becomes harmful after the expiration date, just possibly less effective. Really only one drug was associated with having negative effects after expiration and that was a drug known as tetracycline.


The common recommendation you will get is as follows: Expired medications are probably not harmful to take but may not be as effective. Since there isn't sufficient evidence to recommend that it is OK to take an expired medication, it is recommended that you obtain a medication that is in date. If you are in a bind and must not miss a dose of medication, an expired dose of medication may be an option.


We know how expensive medications such as Cialis can be. We did a little research and did not find any evidence that Cialis can be harmful if taken after the expiration date, it just might not be as effective. Having said that, we do recommend getting and taking medication that is in date.