The Patient's Guide to Clinical Trials
Clinical trials let patients access experimental treatments months or years before they reach the market — often at no cost. This guide walks you through how trials work, how to find one that fits your situation, how to evaluate it with your doctor, and what to expect from enrollment through follow-up.
Why consider a clinical trial?
- Access to new treatments: Most investigational drugs are available years before FDA approval only through trials.
- Specialist-level care: Trial sites are typically major academic medical centers with multi-disciplinary teams.
- Free study-related care: The trial sponsor typically covers the investigational drug, study visits, scans, and labs.
- Contribute to research: Your data helps establish whether a treatment works for the next generation of patients.
How clinical trials are structured
Every trial follows a protocol that defines who can enroll (eligibility), what will be measured (endpoints), how participants are assigned to treatment arms (often randomization with a control group), and how long follow-up lasts. An institutional review board (IRB) reviews and continuously monitors the study to protect participants.
The four phases
- Phase 1 — safety, ~20–100 people, finds a tolerable dose.
- Phase 2 — effectiveness signal, ~100–300 people.
- Phase 3 — pivotal efficacy, often randomized vs. standard of care, ~300–3,000 people. Outcome data is the basis for FDA approval.
- Phase 4 — post-approval surveillance for rare or long-term side effects.
How to find a trial that fits you
- Describe your situation in detail. Diagnosis, stage if cancer, prior treatments tried, current medications, age, and any co-existing conditions. Specificity dramatically improves matching.
- Filter by location. Some trials run only at one center; others have 100+ sites. We let you filter by country, region, or "Near you."
- Read eligibility carefully. Each trial has inclusion criteria (what you must have) and exclusion criteria (what disqualifies you). Common exclusions: certain prior treatments, pregnancy, specific lab thresholds.
- Note the recruitment status. "Recruiting" or "Not yet recruiting" trials are accepting participants; "Active, not recruiting" trials have closed enrollment but are still running.
- Save your top candidates. Bring 2–5 trial NCT numbers to your next appointment.
Questions to ask before enrolling
- What is the purpose of the study, and what specifically is being tested?
- What are the possible benefits, risks, and side effects?
- What treatments would I receive, and how is the assignment decided?
- How long does the trial last, and what is the time commitment per visit?
- Who pays for what? What happens with my health insurance?
- What happens if I am harmed during the trial?
- Can I withdraw at any time, and what happens to my data if I do?
- Will I learn the trial's results, and if so, when?
What happens after you express interest
- Initial screening call — the site asks basic questions to rule out obvious mismatches.
- In-person screening visit — full medical history, exam, often labs and imaging.
- Informed consent — a written document you sign only after all your questions are answered. You can withdraw anytime, even after signing.
- Randomization & treatment — if assigned to receive the investigational treatment, you begin on the protocol's schedule.
- Follow-up — scheduled visits over months or years to track outcomes and side effects.
Where the data comes from
Find a Trial indexes every actively recruiting and recently completed study listed on ClinicalTrials.gov — the US registry where federal law requires most US-based trials to be posted — plus research grants from the NIH RePORTER database. We refresh daily.