Curious about what a clinical trial is? Wondering if you should volunteer to participate?

We asked the National Institutes of Health to help us learn more.

We know: How Clinical Trials Work

What is a clinical trial?

A clinical trial uses human volunteers in a research study designed to answer specific health questions.

Interventional trials used a controlled environment to determine whether experimental treatments are safe and effective. Observational trials use large groups of people in natural settings to study health issues.

Why do people volunteer for a clinical trial?

People often volunteer because they can gain access to new treatments before they are widely available and to make a contribution to health science.

Who can participate in a clinical trial?

Clinical trials are designed to answer specific questions and, therefore, need volunteers who meet particular criteria. Before being selected for a trial, you must meet the criteria. They usually include factors such as age, gender, the type and stage of a disease, previous treatment history, and other medical conditions.

Do I have to give my permission to be part of a clinical trial?

Yes. This is called informed consent. It means the details of the study must be explained to you, including the duration, required procedures, and key contacts, along with the risks and potential benefits of the study. You must sign the document giving your consent before you can participate.

What are the drawbacks of volunteering to participate in a clinical trial?

Drawbacks include:

The treatment you receive may have unpleasant, serious or even life-threatening side effects.
The treatment may not be effective for you.
The study requirements (such as tests, trips to the doctor, hospital stays etc.) may be burdensome.

Are clinical trials safe?

There are no guarantees about the outcomes of a clinical study, but clinical trials are governed by the same ethical and legal codes that apply to medical practice.

Can I leave a clinical trial after I’ve started?

Yes.