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Questions to Ask About a Clinical Trial

A ready-to-use list of questions to ask before joining a cancer clinical trial — about the trial itself, risks and benefits, costs, and how it compares to standard treatment.

AI-assisted and source verified. Not reviewed by a healthcare professional unless specifically stated.

Last updated: 2026-07-14Next planned review: 2027-07-14

How this page was created

Cancer Explained uses AI to organize and translate information from the authoritative sources cited on each page. Automated checks review claims, citations, clarity, duplication, and potential safety concerns before publication. Our content is not currently reviewed by physicians unless a specific qualified reviewer is named on the page. Cancer Explained provides general education and should not replace advice from your healthcare team.

Editorial status — Source verified. This page was created with AI assistance and checked against the sources listed on it. Source checking is not a medical review.

General education — varies by person. Answers genuinely differ between people. This page explains what commonly varies and points you to your care team for your situation.

Human medical review: not completed. At this time, most Cancer Explained content has not been reviewed by a physician or other healthcare professional. Pages with documented human medical review identify the reviewer, credentials, and review date directly.

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NCI source

NCI last reviewed source: 2024-11-18

The short answer

Clinical trials are research studies that test new ways to prevent, find, or treat disease. Before joining one, it helps to understand the trial's purpose, its risks and benefits compared to standard treatment, your rights as a participant, what it might cost, how it could affect your daily life, and what your other choices are. Bring the questions that matter most to you.

  • Ask about the trial's purpose and why researchers think the studied treatment may — or may not — be better.

  • Ask about the possible risks and benefits, and how they compare to standard treatment.

  • Ask how your information is kept private, and what happens if you decide to leave the trial.

  • Ask which costs you'd pay, and which insurance or the study would cover.

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The full explanation.

Why these questions matter

Clinical trials are research studies that test new ways to prevent, find, or treat disease. Considering one adds extra questions on top of a regular treatment discussion — about the study itself, your rights, the costs, and how it fits into your life. Having a list ready helps you cover this ground without missing something important.

These prompts are adapted from questions the National Cancer Institute suggests for people considering a clinical trial.

The essentials

  • What is the purpose of this trial?
  • Why do researchers think the treatment being studied may be better than the current standard treatment — and why might it not be?
  • How long would I be in the trial, and how many visits would it involve?
  • What tests or treatments would I receive, and how will you know if it's working?
  • Who is in charge of my care while I'm in the trial?

About risks, benefits, and your rights

  • What are the possible side effects or risks?
  • What are the possible benefits, and how do they compare to standard treatment?
  • How is my information kept private?
  • If I decide to leave the trial, what options remain for my care?

About costs and daily life

  • Which costs would I be responsible for, and what would insurance or the study cover?
  • Who can help me with insurance questions related to the trial?
  • How would the trial affect my daily life, including travel and any hospital stays?
  • What check-ups would I need after the trial ends?

Comparing your choices

  • What are my other treatment choices, including standard treatment?
  • How do those choices compare to this trial?
  • What happens if I choose not to have any treatment right now?

Make it yours

Clinical trial decisions often benefit from more than one conversation. It can help to:

  • Ask for written materials about the trial to review at home.
  • Bring a family member or friend to the discussion.
  • Ask who to contact — a doctor, nurse, or study coordinator — with questions that come up later.
  • Take time before deciding, if your situation allows it.

The takeaway

A clinical trial is one option among several, not a leap into the unknown. Questions about the purpose, the risks and benefits, your rights, the costs, and how it compares to your other choices can help you decide whether it's worth pursuing for your situation.

Words to know

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Common questions

How many questions should I bring to a clinical trial appointment?

As many as you need. Clinical trials involve more moving parts than standard treatment discussions — purpose, risks, costs, logistics — so it's common to bring a longer list and go through it over more than one conversation.

What if I decide I want to leave a trial after joining?

It's worth asking about this before you join. Ask what options remain for your care if you leave the trial, so you understand the situation ahead of time rather than during a stressful moment.

Is it okay to ask how a trial compares to standard treatment?

Yes. Understanding how the studied treatment compares to standard treatment — and what happens if you choose no treatment at all — is one of the comparison questions worth asking before deciding.

Questions to ask your doctor

Being prepared helps you get the most out of your appointments. Save or print these questions.

Open my question list

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Your next step

Pick the questions that fit your situation, then print or save them.

Build your question list
Quick quiz

Test your knowledge

0 of 4 answered

  1. Q1.What is a clinical trial, according to this article?
  2. Q2.Which question does the article suggest asking about your rights as a trial participant?
  3. Q3.Under 'Comparing your choices,' what does the article suggest asking about?
  4. Q4.What does the article suggest about cost-related questions for a clinical trial?

This quiz checks understanding of educational content only. It is not medical advice. Open this quiz on its own page.

How this page was created

Cancer Explained uses AI to organize and translate information from the authoritative sources cited on each page. Automated checks review claims, citations, clarity, duplication, and potential safety concerns before publication. Our content is not currently reviewed by physicians unless a specific qualified reviewer is named on the page. Cancer Explained provides general education and should not replace advice from your healthcare team.

Editorial status: Source verified This page was created with AI assistance and checked against the sources listed on it. Source checking is not a medical review.

Human medical review: not completed. At this time, most Cancer Explained content has not been reviewed by a physician or other healthcare professional. Pages with documented human medical review identify the reviewer, credentials, and review date directly.

Read more about our editorial process, our use of AI, and our corrections policy.

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Related learning map

How this explanation connects to 13 other things you can explore — related topics, terms, questions, practice, and its NCI source.

Questions to Ask About a Clinical Trial