Questions to ask before joining a clinical trial

You do not need to know research terminology to ask good questions about a clinical trial. Start with what the study is trying to learn, what it would ask of you, and what remains uncertain.

A clinical trial is research. An investigational treatment has not been established as safe and effective for the use being studied. Participation may not help your condition, and there may be risks that researchers do not yet know. The study team should explain the particular study, and your usual clinician can help you consider it alongside your other options.

Understand the purpose

Ask: “What question is this study trying to answer?” Then ask which activities are research and which are part of your usual care. A study may compare different approaches, collect information, or evaluate an intervention; the details matter more than a general description of innovation.

If the study involves an investigational product, ask what is known about it and what remains uncertain. Do not assume that being invited means the study is the best available option for you.

Understand how treatment is assigned

Ask whether you would be assigned to a group by chance, whether a placebo is used, and whether you or the study team would know your assignment. Ask what care each group receives and which usual treatments can continue.

Do not stop or change medicines based on a website, advertisement, or preliminary recruitment conversation. Discuss any proposed changes with the study clinician and the clinician responsible for your care.

Talk through risks and alternatives

Ask the team to explain common risks, serious risks, and important unknowns in understandable language. Ask how you should report a new symptom, whom to call outside office hours, and what happens if you need urgent care.

Also ask about alternatives to joining, including usual care. Understanding these options helps you make a decision without treating participation as the only available path.

Put the schedule into real life

Request a visit outline that includes expected length, location, procedures, home activities, and possible extra visits. Ask whether a family member or caregiver needs to attend and what happens if work, transportation, or another responsibility conflicts with an appointment.

Consider the whole day: travel, parking, waiting, the visit itself, and getting home. A short procedure can still require a substantial time commitment. The visit planning guide can help you organize these questions.

Clarify money and information

Ask which costs the study pays, which may be billed elsewhere, and whether travel or other expenses are reimbursed. If payments are offered, ask when they are made, what conditions apply, and what happens if you leave early. Do not assume that every expense is covered.

Ask who will have access to your information and what happens to information or samples already collected if you stop participating. The answer may depend on the study and applicable requirements, so request an explanation specific to the consent document.

Give yourself room to decide

Ask for time to read the consent materials and discuss the study with someone you trust. Tell the team if you need language support or a more accessible format. You can ask the same question again when an answer is unclear.

Participation is voluntary. Ask how to tell the team if you decide to leave and what safety follow-up they recommend. Leaving a study and deleting previously collected research information are different questions; ask about each.

Use the participation question builder to make a short list you can print and bring to a conversation. You do not need to enter a diagnosis or personal medical details. The list helps prepare a discussion; it does not determine whether you should enroll.