When you use a medicine, you expect it to be as safe as possible. No medicine is completely free from risk, but there are many checks in place to ensure that medicines are as safe as possible before becoming available for GPs and other healthcare professionals to prescribe, or before you can buy them over the counter.
UK medicine licences
In the UK, before any medicine can be used to treat people, it has to be licensed. Licences are only granted if 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.
Licences can be granted by:
- the Medicines and Healthcare products Regulatory Agency (MHRA) – an executive agency of the Department of Health that ensures that medicines and medical devices work and are safe, including granting licences for their use in the UK
- the European Medicines Agency (EMA) – a health regulatory agency that can grant licences to cover the use of medicines in the European Union (EU); it ensures that medicines are available and used in the same way across all EU member states
Before a licence can be granted, the medicine needs to be developed and tested.
Developing a medicine
Potential medicines are thoroughly researched using tissue culture and computer analysis techniques.
After this, they may be tested in animals. All new medicines are required by law to be tested for safety, quality and effectiveness. Data is needed from two separate species of animal before a medicine can be used in humans.
Clinical trials
Clinical trials are research studies carried out in human volunteers and patients that carefully test the safety and effectiveness of medicines, using strict criteria.
If clinical trials are going to be carried out in the UK, the manufacturer of the medicine must first apply to the MHRA for permission to test its medicine.
In the UK, clinical trials are sponsored by:
- the pharmaceutical industry (companies who make medicines)
- research charities
- research councils
- the NHS
A quarter of the world’s top 100 medicines were developed in this country, which is a leader in clinical research.
See the Health A-Z topic about Clinical trials and medical research for more information.
Finding and developing new medicines takes around 10 to 12 years. It is also a very expensive process. Estimates vary, but it may cost around £550 million to develop a new medicine, from its discovery to gaining a licence.
Stages of research
Four levels of clinical trials are used to investigate a new medicine:
- phase 1 – the medicine is tested in small numbers of healthy volunteers (up to 100 people) to find out how it works in the body and whether side effects increase at higher doses
- phase 2 – the medicine is tested in moderate numbers of people (several hundred) with a particular condition or disease to see how effective it is, and to identify common, short-term side effects
- phase 3 – information about the medicine is gathered from a larger number of people (often several thousand) to see how well it works and how safe it is
- phase 4 – after it has been licensed, post-marketing studies are used to monitor the medicine on an ongoing basis in real world conditions (possibly in several thousands of people) to see if there are any unexpected side effects or if the medicine causes problems in certain categories of people
See the Health A-Z topic about Clinical trials and medical research - phases of trials for more information.
