What is a clinical trial: safe testing with volunteers
A clinical trial tests a new treatment, test or approach in volunteers, following a precise plan called a protocol. It shows whether the new option is better than, as good as or less harmful than standard treatment.

01Short answer
02Simple explanation
A precise protocol.
Ethics oversight.
Voluntary consent.
Leave at any time.
03Scientific explanation
NCI: clinical trials study whether new treatments are safe and effective, and they can be an option for people with cancer.
NCI: new treatments are tested step by step, from the laboratory to clinical trials; only those proven safe and beneficial become standard care.
04What happens in the body?
Types
Treatment, prevention, diagnosis and quality-of-life trials.

Standard treatment
The best current treatment, used for comparison.

How to read the news
Research news brings hope, but not every advance suits everyone. Look at who it was tested in, at what phase and in how many people.
Talk to your doctor
Show your doctor what you have read; they will explain how it relates to your diagnosis and treatment. Do not change your treatment on your own.
05From research news to a conversation: four steps
Read, check, ask, decide together.







06Key points at a glance
| Topic | In brief |
|---|---|
Types | Treatment, prevention, diagnosis and quality-of-life trials. |
Standard treatment | The best current treatment, used for comparison. |
How to read the news | Research news brings hope, but not every advance suits everyone. Look at who it was tested in, at what phase and in how many people. |
Talk to your doctor | Show your doctor what you have read; they will explain how it relates to your diagnosis and treatment. Do not change your treatment on your own. |
07Key terms
- Protocol
- The written plan of a trial.
- Informed consent
- Voluntary agreement after a full explanation.
- Clinical trial
- Testing a new treatment with volunteers.
- Evidence
- A result confirmed by reliable research.
08Key points
- Read.
- Ask.
- Decide.
- Check the source.
- Talk to your doctor.
09Frequently asked questions
Will I be a guinea pig?
No; trials are protected by strict rules and your rights are kept.
Do I have to pay?
Often the sponsor covers trial costs; ask for details.
Is this advance right for me?
Only your treating doctor can say, based on your diagnosis, stage and condition.
10Questions for your doctor
Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.
Will I be a guinea pig?
Do I have to pay?
Is this advance right for me?
12Sources
- National Cancer Institute. What Are Clinical Trials?
- National Cancer Institute. Informed Consent in Clinical Trials
- National Cancer Institute. NCI Dictionary of Cancer Terms: clinical trial
- National Cancer Institute. Phases of Clinical Trials
- National Cancer Institute. Using Trusted Resources
- U.S. Food and Drug Administration (FDA). Step 3: Clinical Research
- U.S. Food and Drug Administration (FDA). Learn About Expanded Access and Other Treatment Options
- European Union. Clinical Trials Information System (CTIS) — public search
- World Health Organization (WHO). International Clinical Trials Registry Platform (ICTRP)
- National Cancer Institute. NCI Dictionary of Cancer Terms: phase I clinical trial
Types
How to read the news
Talk to your doctor