Recent studies have brought to light evidence to suggest that drug companies have been over zealous when it comes to labelling pharmaceuticals with their expiry date.

A small case study was conducted recently when it was discovered that a batch of pharmaceutical drugs was taken to the Antarctic via the hot tropics, stored in the cold climate then brought all the way back to the UK.  The drugs were tested and found to be just as effective as the day they were produced, even though they were four years past the expiry date recommended by the manufacturer. 

There is also an initiative in the USA called the shelf life extension program, ran by the federal government.  The program stores all kinds of medical drugs in very tightly controlled environments, and then sampled and tested extensively to see how effective they are past their expiry date.  Sometime these drugs can have their shelf life extended by up to 10 years.

However it is not all black and white.  Some drugs may last for many years on the shelf with fluctuating conditions like light and heat, while others may be very sensitive to heat.  This variation of the drugs ability to withstand the elements means that there is not a one size fits all approach when it comes to using the drugs after their expiry date.

Experts agree that the more powerful the drug in terms of it therapeutic value, the more cautious you have to be in discerning if it can be used past its marked date.  If it is a medicine for people with epilepsy for example, then if the potency of the drug has declined due to exposure to heat , this puts the user in a very dangerous scenario as the drug may not be able to hold an epileptic seizure at bay.