What you should be told about a clinical trial

This page is about what you must be told before you take part in a clinical trial.  

Before you take part

By law, researchers must explain to you what a trial involves before you agree to take part.

They must tell you

  • What the trial is trying to find out
  • What treatment you will be asked to have
  • What the likely risks and side effects will be
  • What the benefits may be
  • What tests or check-ups you will be expected to have
  • How often you will be seen in follow up appointments and for how long
  • Whether any of your blood or tissue samples will be kept or used for further research

Patient information leaflet

Full information about a trial should all be included in the patient information sheet (PIS), which may be called a patient information leaflet (PIL). The research team will give you a copy of the PIS to take home and read in your own time.

You can refer back to the patient information sheet when you are deciding whether to take part in the trial or not. You can also discuss it with your friends, family, GP, specialist or nurse.

Giving your consent

Before entering the trial you must sign a statement to say you have been told, and understand, what taking part in the trial means. This is called informed consent. 

You can't enter a trial without signing your agreement. You are entitled to ask any question you like if there is anything you don't understand.

Informed consent is an ongoing process throughout the trial. So you should always be able to ask questions, and get answers to them, while you are in the trial.

Information about side effects

If the trial is investigating a very new treatment, the research team may not know much about the side effects yet. But you should be told everything they do know that is relevant.

If you want to leave a trial

Remember that you can withdraw from a trial at any time, without giving a reason. You will then be entitled to the standard treatment for your type and stage of cancer.

Related information

Last reviewed

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

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