is it safe to take metronidazole after it's expiration date?


Manufacturers determine the stability of any medicine based on three factors - time, temperature and humidity. Usually the higher or longer one of these is, the shorter the life of a product will be.

They will also declare an expiry or use by date with a margin of safety to account for the variations of temperature and humidity whilst being used by the patient. However there are no set standards for how large this margin may be and some products (liquids and creams for example) will often have a narrower margin than tablets stored in ideal conditions.

Although I cannot recommend use of any product outside the manufacturers expiry date, the patient will know best how well the product has been stored and how long it is since it expired. They can then make their own assessment - a few weeks will probably not be a problem, but months or years will most likely mean the product has degraded to a greater or lesser extent.

I hope this helps.


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Nigel Simmons


I am happy to answer general questions on medicines and hospital care. If possible, please use approved / chemical names rather than brands which are not internationally recognised. Like all health professionals I am bound by a duty of care which prevents me giving detailed information about medication or treatment of people other than the questioner. I will endeavour to help wherever possible or point towards more appropriate advice. If however your question crosses too far into patient confidentiality, I hope you will understand why I cannot answer your question. Consider.. would you want me to discuss your care with a friend or relative without your knowledge?


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