About clinical trials

More information about clinical trials

Clinical trials are performed to collect information on new medicines before they are used in everyday practice.  This summary aims to provide some basic information about clinical trials. It includes an explanation of what clinical trials are, who and what they involve.

What is a clinical trial?
Clinical trials in humans is a research study that carefully tests a new medicine in people, once it has been shown to be safe in several animal species.

Why are clinical trials important?
Before a new medicine can be used widely it must be tested to make sure it is of benefit to patients and that it is safe. Clinical trials are the most reliable way of gathering this information.  Over the years, new methods of prevention, diagnosis and treatment have been developed through performing clinical trials and this has improved patient care.  However, not all clinical trials result in new treatments becoming available.  Sometimes the clinical trial will discover that the treatment does not work, or that there are too many side-effects.  This information is still valuable though because it allows the researchers to rule something out and try a different way. 

What are the different stages of clinical trials?
Every new medicine being tested must go through 3 stages of clinical trials (called Phases I, II and III) before it is used in everyday practice.  A Phase IV clinical trial might sometimes follow after the medicine has started being used in everyday practice.

For a more detailed explanation of the different Phases in clinical trials.