Last updated: 04 October 2011
When you use a medicine, you expect it to be as safe as possible. No medicine is completely free from risks, but there are lots of checks in place to ensure that medicines are as safe as they can be before they become available for doctors and other healthcare professionals to prescribe, or before you can buy them over the counter.
Checks are also in place to ensure no new, unexpected problems arise. Your healthcare professional will usually make an assessment of risk versus benefit and decide the best option for you.
Before any medicine or medical device can be used to treat people in the UK, it has to be licensed by the Medicines and Healthcare products Regulatory Agency (MHRA, see Useful links). Licences are granted only if the high standards of safety and quality are met and the product works for the purpose intended. There are also rigorous standards for medicine manufacturers and wholesalers.
All new drugs are required by law to be tested for safety, quality and effectiveness under the Medicines Act 1968. Data is needed from two separate species of animal before a drug may be used in humans.
Before any potential drug is tested in animals, it will have been thoroughly researched using tissue culture and computer analysis techniques.
Continue to next section: Who looks after the safety of medicines?