Clinical trials help bring safe, effective treatments to the world. Here's a clear, friendly guide to what they are, how they work, and what participating could mean for you.
The Basics
Clinical trials are carefully designed research studies that test new medical approaches in people — and they're a cornerstone of medical progress.
A clinical trial is a voluntary research study that looks at whether a new treatment, drug, device, or approach is safe and effective for people. Every approved medication you've ever taken went through clinical trials first.
Trials follow strict rules called a protocol — a detailed plan created by researchers and reviewed by independent ethics boards to protect participants at every step.
Trials can test drugs, devices, therapies, prevention strategies, and more
Multiple safety layers and ethics boards protect every participant
Trials have led to breakthroughs in cancer, heart disease, diabetes, and many more
The Journey
Each phase builds on the last — gathering more evidence about safety and effectiveness. Navigate through the journey below.
Before any human testing begins, scientists study a promising treatment in the lab and sometimes in animal models. This critical first step helps researchers understand how a treatment works, how it behaves in living systems, and whether it's safe enough to test in people.
The treatment is given to a small group of people for the very first time. The primary focus is on safety: identifying side effects, understanding how the body processes the treatment, and finding the right dosage range. Participants are closely monitored every step of the way.
With safety established, a larger group of patients receives the treatment to see if it actually helps the condition it's designed for. Researchers also continue monitoring safety and work to identify the optimal dose and method of delivery.
This is the big one. The treatment is tested in large, diverse groups of people and compared to existing treatments or a placebo. Researchers confirm effectiveness, monitor side effects at scale, and gather the critical data needed for regulatory approval.
After a treatment is approved and available to patients, Phase 4 studies continue tracking its long-term safety and effectiveness in real-world conditions. These studies involve larger, more diverse populations and can uncover rare side effects or new benefits.
From Lab to Medicine Cabinet
The medicines and vaccines that define modern life — from painkillers to life-saving vaccines — all started as a clinical trial.
Scroll to explore · Years reflect initial trial or landmark approval date
Your Care Team
Clinical trials are a team effort. Here are the people working together to make sure each study is safe, ethical, and scientifically sound.
The lead doctor or scientist who designs and oversees the study. They are responsible for your safety and the integrity of the research.
Nurses, coordinators, pharmacists, and data specialists who manage day-to-day operations and are your main points of contact.
An independent group that reviews and approves the trial to ensure it's ethical and that participant rights and welfare are protected.
An independent committee that monitors ongoing results and can pause or stop a trial if safety concerns arise.
The organization funding the trial — often a pharmaceutical company, university, or government agency like the NIH.
The most important member of the team. Your voluntary participation makes medical breakthroughs possible for future patients.
Always Protected
Participating in a clinical trial is always voluntary, and your safety and dignity come first.
You'll receive a clear, written explanation of the study — its purpose, procedures, risks, and benefits — before you decide to join.
You can leave the trial at any time, for any reason, without penalty or loss of benefits you're otherwise entitled to.
Your personal information and medical data are protected by strict regulations like HIPAA throughout the study.
You have the right to ask your research team any question at any point — and to receive a clear, honest answer.
You'll continue to receive standard medical care and be monitored for any side effects throughout your participation.
You may request information about the study results and how the research contributed to medical knowledge.
What to Expect
Here's a simplified look at the typical experience from start to finish — every step designed with your wellbeing in mind.
Find a trial that fits your health situation and interests
Health checks confirm you're a good fit for the study
Review all details and ask every question you have
Follow the study plan with close support from your care team
Monitoring continues even after the active study ends
Common Questions
Not all trials use placebos. Many compare a new treatment to the current best available therapy. If a placebo is used, you'll be told about this during the informed consent process before you join. You'll never be left without necessary medical care.
In most clinical trials, the study treatment, tests, and doctor visits related to the research are provided at no cost. Some trials even cover travel expenses or provide a stipend. Your research team will explain all costs and coverage during the consent process.
You can search ClinicalTrials.gov — a database of thousands of studies worldwide. Your doctor can also help identify trials suited to your condition. Many hospitals and cancer centers have dedicated offices to help patients explore clinical trial options.
Your research team monitors you closely for side effects throughout the study. If you experience any, report them right away — your team is trained to manage them. If a side effect is serious, your treatment may be adjusted or you may leave the trial while continuing to receive care.
Yes. Your regular doctor remains part of your care. The research team works alongside your existing healthcare providers. It's important to keep all of your doctors informed so they can coordinate your care effectively.