Get Involved with Clinical Research

The health of millions has been improved because of advances in science and technology, and the willingness of thousands of individual volunteers to take part in clinical research. Research volunteers, whether patients or healthy subjects, play a vital role in medical research. More than 350,000 individuals from around the world have participated in clinical research at the NIH Clinical Center since the hospital opened in 1953.

Learn more about ways to participate in clinical trials and find additional patient resources at the NIH Clinical Center page “Participate in Clinical Studies”.

Clinical studies—medical research studies (sometimes called trials or protocols) in which people participate as volunteers—are a means of developing new treatments and medications for diseases and conditions. These trials follow strict rules that are monitored by the National Institutes of Health (NIH) and the Food and Drug Administration (FDA), especially when they involve new drugs. Clinical studies do not necessarily involve drugs—some, for instance, are designed to observe the risk factors and markers associated with a disease.

Clinical trials are conducted in “phases,” and each phase serves a different purpose to help researchers answer different questions:

  • Phase 1—Researchers test an experimental drug or treatment in a small group of people (20–80) for the first time. The purpose is to evaluate its safety and identify side effects.
  • Phase 2—The experimental drug or treatment is administered to a larger group of people (100–300) to determine its effectiveness and to further evaluate its safety.
  • Phase 3—The experimental drug or treatment is administered to large groups of people (1,000–3,000) to confirm its effectiveness, monitor side effects, compare it with standard or equivalent treatments, and collect information that will allow the experimental drug or treatment to be used safely.
  • Phase 4—After a drug is licensed (approved by the FDA) or treatment is launched, researchers track its safety, seeking more information about a drug or treatment’s risks, benefits, and optimal use. These long-term studies involving large groups of participants continue to see if any unexpected side effects occur in a small percentage of individuals.

Patients can take part in clinical studies covering a wide range of medical diseases, conditions, and rare disorders affecting both children and adults. The spectrum of diseases being studied includes AIDS, aging, alcohol abuse and alcoholism, allergy, cancer, digestive and kidney problems, diabetes, eye disorders, infectious diseases, genetics, mental health, neurological disorders, stroke, and others.

Healthy volunteers who seek to advance knowledge about causes, progress, and treatment of disease may also participate in clinical studies. They provide important medical information to researchers by helping them compare how healthy people differ medically from those who have a specific disease.

Because the research is funded by the Federal Government, there is no cost for care received at the NIH Clinical Center and volunteer subjects become partners in a special relationship with members of the research teams in the search for better ways to treat disease.

This page was last updated on Monday, January 10, 2022