Safety in clinical trials

This page tells you about how you are protected when you take part in a clinical trial. There is information about

Safety measures in trials

Treatments are thoroughly tested in laboratory research Open a glossary item

before they are ever tested with groups of patients. Then, treatments must get through testing with patients in phase 1 and 2 trials before they can be used in larger phase 3 trials Open a glossary item

There are many safety measures in place for patients taking part in trials.

The team running the trial must:

make sure that other doctors review the trial plan (protocol) and that it is approved by an ethics committee
arrange a data monitoring committee (DMC) who will review the trial at regular time points and can stop or modify the trial if they need to
make sure they have insurance in place in case they need to pay compensation for any reason
protect your privacy at all times
tell you all about the benefits and risks before you agree to take part

Compensation for people taking part in trials

The indemnity cover (insurance) pays compensation to you if you are harmed because of the trial. Under UK and European regulations, the organisation or drug company funding the trial has to have insurance. If they don't, the ethics committee may not approve the trial.

In practice, several different bodies may provide cover for you:

the NHS is liable for any clinical negligence if you have treatment in an NHS hospital or clinic as part of a trial
universities provide insurance for university researchers if any harm results from the design of a trial
drug companies are responsible for insuring against any harm caused by the drugs being investigated

Testing licensed drugs

It is slightly different if you are taking part in a phase 4 trial for a drug that is already licensed for treating cancer.

There may not be specific extra insurance to cover the use of the drug. It would have already been tested and found safe to use. So extra insurance is not necessary.

You would usually be covered by the insurance held by the doctor and hospital treating you. You can ask your doctor or research nurse about trial insurance if you are worried.

References

Oxford Handbook of Clinical and Healthcare Research (1st edition)
R Sumantra, S Fitzpatrick, R Golubic and others
Oxford University Press, 2016

UK Policy Framework for Health and Social Care Research
NHS Health Research Authority website, last updated on 10 Jan 2025
Accessed June 2025

Good clinical practice for clinical trials
Medicines and Healthcare products Regulatory Agency
GOV.UK website, 18 December 2014. Last updated 22 July 2024
Accessed June 2025