When medicines are manufactured, by law they have to be given an expiry date. This is the date after which they are not expected to be as effective as they should.
Medicines lose their effectiveness over time because the chemicals in medicines can be broken down to inactive products by the effects of heat, light or oxygen. At worst, taking old medicines can be fatal if they’re for the treatment of serious conditions.
Expiry dates can vary widely between different medicines and forms of medicine. For example dry tablets are likely to have a later expiry date than liquids.
Medicines to watch out for
You need to be particularly careful with certain medicines for life-threatening conditions like:
- EpiPen® for the treatment of severe allergic reaction
- glyceryl trinitrate or GTN for angina and chest pain
- insulin for diabetes.
Eye drops are another special case. They can become contaminated with bacteria. A general rule is to never use eye drops after the expiry date, and to throw them out 28 days after you’ve opened them, even if it is before the expiry date.
Safe storage of medicines
For your medications to stay effective until the expiry date, you need to store them properly. Follow the instructions on the packaging, which might include storage below 25°C, in a dark place or in the refrigerator at about 4°C. And out of reach of children.
And it’s a good idea to clean out your medicines cupboard every 6-12 months.
What to do if you've been taking expired medicines
If you discover that you have been taking expired medication, talk to your pharmacist or your doctor. You might need to get a fresh, fully active batch.
It's a good idea to check all of your medicines regularly and get rid of any that are out of date or that you no longer need. Take the unwanted medicines to your pharmacy for safe disposal – flushing them down the toilet or putting them in the rubbish can harm the environment.
Last reviewed: May 2016