Questions to Ask Your Doctor About Clinical Trials

About the trial itself

Start with the basics. Understanding the purpose and design of the trial will help everything else make more sense.

1. What is the purpose of this trial?

Ask whether the trial is testing a new drug, a new combination of existing drugs, a device, a surgical technique, or a behavioral intervention. Knowing the goal helps you understand what the researchers hope to learn and how your participation contributes.

2. What phase is this trial in?

The phase tells you how much is already known about the treatment. A Phase 1 trial is exploring safety for the first time. A Phase 3 trial has already shown promise in earlier studies. Each phase carries a different balance of unknowns and potential benefits.

3. How is this treatment different from what I am currently receiving?

Your doctor can compare the trial treatment to your current standard of care. Ask specifically whether the trial treatment works through a different mechanism, targets a different pathway, or offers advantages that existing options do not.

4. Is there a placebo group, and could I be assigned to it?

If the trial uses a placebo, ask what the chances are of being in the placebo group. In some trials it is 50/50; in others the odds favor the treatment arm. Also ask whether you would still receive standard treatment alongside the placebo.

5. Who is sponsoring this trial?

The sponsor might be a pharmaceutical company, a government agency like the NIH, or an academic institution. Knowing the sponsor can help you understand the motivations behind the research and where the results will be published.

About risks and side effects

Every treatment carries risks. A clinical trial introduces additional unknowns because the treatment is still being studied.

6. What are the known side effects so far?

If the treatment has been tested in earlier phases, researchers will have a list of observed side effects. Ask for the most common ones, the most serious ones, and how often each occurs.

7. How do the risks compare to my current treatment?

This is essential context. If your current treatment has significant side effects and the trial treatment's safety profile looks similar or better, the calculus changes. Your doctor can help you make this comparison.

8. What happens if I experience a serious side effect during the trial?

Ask about the protocol for managing adverse events. Find out who you should contact, how quickly you will be seen, and whether the trial will cover the cost of treating side effects caused by the study drug.

9. Could participating in this trial affect my future treatment options?

Some treatments can make you ineligible for other therapies later. For example, certain immunotherapies may disqualify you from future trials. Ask your doctor whether joining this trial could close doors down the road.

About logistics and daily life

Clinical trials require time and commitment. Understanding the practical demands will help you decide whether participation is realistic for your situation.

10. How long does the trial last?

Ask for the total duration, including any follow-up period after the active treatment ends. Some trials involve months of follow-up visits even after you stop receiving the study treatment.

11. How often will I need to visit the clinic?

Some trials require weekly visits; others are monthly. Ask whether any visits can be conducted via telehealth and how long each appointment typically takes.

12. Where will the trial take place?

If the trial site is far from your home, factor in travel time, transportation costs, and potential overnight stays. Some trials reimburse travel expenses; others do not.

13. Will the trial interfere with my work or daily routine?

Ask about time-intensive phases, such as an initial induction period that might require daily visits for a week. Understanding the schedule up front helps you plan around work, childcare, and other responsibilities.

14. What costs will I be responsible for?

The study treatment is typically provided at no cost. However, you may still be responsible for standard-of-care costs like doctor visits, blood tests, and imaging that you would need regardless of the trial. Ask what your insurance will cover and what the trial sponsor will cover.

About alternatives and your rights

A clinical trial is one option among several. Make sure you understand the full picture.

15. What are my other treatment options if I do not join this trial?

Your doctor should outline all available alternatives, including approved treatments you have not yet tried, other clinical trials, and the option of supportive care without active treatment.

16. Why do you think this trial is a good option for me specifically?

This is perhaps the most important question on the list. Your doctor knows your medical history, your treatment responses, and your overall health. Their reasoning for recommending or not recommending a specific trial carries significant weight.

17. Can I leave the trial at any time?

The answer should always be yes. Participation in any clinical trial is voluntary, and you have the legal right to withdraw at any point without it affecting your standard medical care. But ask what the process looks like: Will there be a gradual taper of the study drug? Will you need a final set of tests?

18. What happens when the trial ends?

If the treatment works for you, ask whether you will continue to have access to it after the trial concludes. Some sponsors offer "compassionate use" or "expanded access" programs that allow continued access to a study drug before it is commercially available.

19. Will I find out whether I received the treatment or the placebo?

In blinded trials, participants are often "unblinded" after the study ends, meaning you will learn which group you were in. Ask when this information will be shared and whether the results will be published.

20. Who can I contact with questions during the trial?

Get a specific name and phone number. You should have 24/7 access to someone on the research team in case of urgent concerns. Also ask about the role of the patient advocate or research coordinator, who can help navigate non-medical questions.

Tips for your appointment

Bring a trusted friend or family member to your appointment. Two sets of ears catch more than one, and they can help you remember details afterward. Take notes or ask whether you can record the conversation.

Do not feel pressured to decide on the spot. A reputable research team will give you time to think, consult with your family, and seek a second opinion. If anyone pressures you for an immediate answer, consider that a red flag.

The ClinicalTrials.gov registry is a useful resource for reviewing the full details of any trial, including its design, eligibility criteria, and contact information.

Next steps

Ready to start the process? Our guide on how to join a clinical trial walks you through each step, from finding a trial to your first screening visit. If some of the eligibility language is confusing, our guide on reading eligibility criteria translates the medical jargon.

TrialFinder makes it easy to browse trials by condition with all the technical language translated into plain English. Find a trial that interests you, then bring this question list to your next doctor's visit.