Medicine expiry dates

Expiry date printed on a medicine pack

We are all familiar with ‘best-before’ and ‘use-by’ dates on food. Medicines are very similarly labelled.

If you look at the packet of your most recent medication, you will see stamped on it somewhere, an expiry date. But what does this expiry date really mean?

Although generally not recommended, we may sometimes choose to eat certain foods beyond their ‘best before’ date. But can we do the same with medicines?

Is it really necessary to throw away, and waste, unused medicines?

Why do drugs have an expiry date?

By law, pharmaceutical manufacturing companies are required to set a date from the date of manufacture, usually 2 or 3 years in the future, and up until this time, they guarantee 100% efficacy of the product. This is the expiry date of the medicine.

This is on the assumption that the product is stored correctly, and the packaging remains intact. Medicines are susceptible to moisture and extremes of temperature, light, and heat. And, always store out of reach from children!

What do expiry dates mean? When does it become unsafe to take a medicine?

For example, if the expiry date on the box reads ‘Expiry April 2024’, you shouldn’t take this drug after 30th April 2024.

Sometimes there may be a ‘use-by’ date – and for example if it reads ‘use-by April 2024’ – you shouldn’t take this after March 31st 2024.

At present, there is no change to the UK recommendations, and you are still not advised to take medicines which have passed their expiry date.

However, this does not mean the medication would be ineffective.

Expiry dates – the extent of the problem

Destroying and replacing drugs which have reached their expiry dates is a costly business around the world. In the United States, this is estimated to cost an incredible $765 billion per year!

Take the example of stockpiling drugs for the Armed Forces. Ensuring enough drugs are always available, up-to-date, and in-date is a huge and expensive task.

Governments are also required to store antibiotics, antivirals, and vaccines for the population in case of need. This can be hugely expensive and lead to massive wastage. A good example is the £473 million spent in the UK stockpiling Tamiflu for the predicted bird flu epidemic – which never arrived! These antivirals have now passed their expiry date and should not be used – but is this really the case?

Do expiry dates really matter? 

If expiry dates could be extended, this could have enormous potential advantages.

Research about drug expiry dates

In 2012, two California scientific researchers, Lee Cantrell and Roy Gerona discovered a hidden supply of medicines, some of which predated 1969! Knowing these medicines were more than 30–40 years old, they set out to analyse these drugs. This included a variety of different medicines, including pain killers, antihistamines, and stimulants – all of which had remained in sealed containers.

The results were amazing! 12 out of the 14 substances analysed were still 100% potent! Read the full story: That Drug Expiration Date May Be More Myth Than Fact.

In another study, investigators looked at the potency of drugs sent back from the British Antarctic Survey. These drugs had a prolonged, perilous journey by sea, to reach the Antarctic station, and are often stored in transit, on a ship, at sub-zero temperatures, and in high humidity. 

Five of these drugs were tested after they had been returned to the UK in just these circumstances, having passed their expiry dates: atropine, nifedipine, flucloxacillin, bendroflumethazide, and naproxen.

All were found to be stable, and could indeed have been used.

The expiry date on a drug packet is the last date a drug company will guarantee the drug content and stability when stored in the recommended conditions and in the original packaging

This date is not necessarily the point at which the drug becomes ineffective or dangerous, and for many medications, this window may be far longer than the usual two-to-three-year expiry date

Lead study author Dr. Emma Browne of the British Antarctic Survey Medical Unit in Plymouth, UK.

A very recent 2019 review of the available medical literature concluded that most drugs are effective for more than 5 years after their expiry date.

Why don’t pharmaceutical companies just change the drug expiry dates?

Drug companies are only required to run tests on their medicines up until the date they expire – not beyond.

In fact, it suits them not to have to do this, because they recoup the financial benefit from the cost of replacing these drugs.

In 1986 the American Defence Department, in conjunction with the FDA, set up the Shelf Life Extension Programme. They then regularly tested medicines to check their potency, and were able to continue to use those which had passed their expiry date but retained their potency. In 2006, for example, they tested 122 drugs which had passed their expiry dates, and found two thirds of them were stable.

The cost benefit of testing these drugs and reusing those which are still potent even though they have passed their expiry date – is huge. In 2016, as part of this programme, the US government spent $3.1million testing these drugs. But by not replacing those that were still potent, they saved the country $2.1 billion!

However, despite this knowledge, efforts to get pharmaceutical companies to extend the expiry dates on their medicines, have so far failed.

So – is it safe to use medicines beyond their expiry dates?

For the time being, it is still highly recommended you only take medicines within the expiry date wherever possible.

However, in difficult situations, where there is no realistic alternative, studies suggest that most medicines are likely to be safe and effective, even after their expiry dates.

Which medicines should never be used beyond their expiry dates?

There are some medicines which should always only be used within their expiry dates, whatever the circumstances.

These are listed below –

  • Liquid preparations of antibiotic made up by the pharmacist. These do degrade and only have a shelf life of 1–2 weeks after dispensing.
  • Eye drops/ointments – discard the bottle/tube after 4 weeks as these may become contaminated with bacteria and cause eye infections
  • The antibiotic tetracycline – this can have a dangerous effect on the kidney.
  • Glycerine trinate (GTN) – for angina.
  • Insulin – for diabetes.
  • Epi-pen – for severe allergy / anaphylaxis.

What to do with medicines past their expiry dates

Medicines past their expiry dates should be returned to a pharmacy for safe disposal.

How can I manage my medicines better?

Unused medicines obtained on prescription cost the NHS around £300 million per year!

It’s important to only order what you need, and to take care of your medical supplies, to reduce wastage.

If you take a number of medicines, or have a long term health condition, you can make an appointment at your pharmacy to have a Medicines Use Review.

Further reading