Adults across the UK are putting themselves at risk by using out-of-date medicines, experts have said.
Health workers urged people to take note of the expiry dates on medication after research suggested that 62% of adults have products in their medicine cabinets which have gone past their use by date.
The study, conducted on behalf of over the counter medicine range Care, suggests that on average there are more than two products in each medicine cabinet which have gone past their expiry date.
Researchers say this figure means that medicine cabinets across the UK have stocked up an estimated 73m out of date products.
The study, conducted on 5,000 people, also found that a quarter of British adults have knowingly taken medicine which is out of date.
And 7% of people do not think medicines have an expiry date.
London-based GP Dr Sarah Jarvis said: "It is extremely worrying to hear so many of us are taking out of date medicines.
"Just like food that goes off, medicines past their expiry date can deteriorate and make you ill. You need to be particularly careful with your eyes, nose or a wound as these areas are especially prone to letting in bacteria."
English Pharmacy Board member Sid Dajani added: "People are risking their lives by not taking the use by dates on their medicines seriously.
"The danger is what they don't do for you - anti-seizure drugs resulting in fits, people with asthma suffocating because their blue inhaler doesn't work or pregnancy tests showing a false negative because the active HCG reagent is too old.
"I urge everybody to check the use by date before taking medication, and to return out of date medicines to their local pharmacy where they'll be disposed of safely."
The research also showed that two-fifths of adults do not read patient information leaflets and 12% admitted that they guess the correct dosage.
Care spokeswoman Leanne Doughty added: "It is essential that families hold on to the packaging and patient information leaflets to ensure safe, effective dosage - and to check their medicines are in date."