How long does medicine last once it's opened?

Most of us have a cupboard with a few half-used bottles, tubes and blister packs in it. But how do you know if they're still OK to use? The answer depends on the type of medicine, whether it's been opened, and how it's been stored.

Check the expiry date first

Every medicine has an expiry date on the pack, usually marked "EXP". This is the date until which the manufacturer guarantees the medicine is safe and works as it should, as long as it's unopened and stored correctly. After this date, don't use it.

Look for "use within" instructions

Some medicines have a shorter life once they're opened, and the label or leaflet will say so, for example "discard 28 days after opening". This applies especially to:

• Eye drops, which are often only good for 4 weeks after opening, because bacteria can get into the bottle.
• Liquid medicines, such as some children's medicines and cough mixtures, especially those you mix from a powder.
• Creams in tubs, which can pick up germs from your fingers more easily than creams in tubes.
• Nasal sprays and some inhalers.

It helps to write the date you opened a bottle or tube on the label, so you know when it needs replacing.

If a medicine looks, smells or feels different, for example if tablets are crumbly or discoloured, or a liquid has changed colour or gone cloudy, don't use it, even if it's still in date.

How to store medicines

• Keep them in a cool, dry place out of direct sunlight. Most medicines should be stored below 25°C unless the label says otherwise.
• Avoid the bathroom, as heat and steam can damage medicines. A high kitchen cupboard away from the cooker is often better.
• Keep medicines in their original packaging, with the leaflet, so you always have the instructions and expiry date.
• Store medicines that need refrigerating in the fridge, but don't let them freeze.
• Always keep medicines out of reach and sight of children, ideally in a locked cupboard.

How to get rid of old medicines

Don't put old or unwanted medicines in the bin or flush them down the toilet, as they can harm the environment and be found by children or pets. Instead, take them to a pharmacy. Most pharmacies will take them back and dispose of them safely for free.

Have a regular clear-out

Go through your medicine cupboard every few months. Take out-of-date or unwanted items to a pharmacy, and replace the basics you've used, so they're there when you need them.

The short answer

Unopened medicines last until the expiry date on the pack if stored properly. Once opened, some, especially eye drops, liquids and creams in tubs, need using within a few weeks, so check the label. Store medicines somewhere cool and dry, and return old ones to a pharmacy.