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Clinical research studies with human volunteers answer specific questions about new therapies or new ways of using known treatments to prevent, control, or treat diseases. The studies may be sponsored by pharmaceutical and biotech companies, cooperative groups supported by government grants, or doctors.


Study participants volunteer to receive treatments according to a detailed testing procedure and under the close supervision of a physician and other research professionals. Physicians who conduct clinical trials have to be qualified through training and experience.

A committee called the Institutional Review Board oversees the study at the research site to help protect the participants’ rights and welfare.

Types of Clinical Trials

The different types, or phases, of clinical trials are designed to answer different questions during the development of new medications or treatments.

•   Phase I - Generally involves a small group (10 to 50 participants) of healthy volunteers over a period of several weeks.

•   Phase II - Involves a larger group (80 to 300 participants) of volunteers who have a specific disease or condition. Phase II studies can run from several weeks to two years. You may receive the study treatment, the existing standard treatment, or a placebo (inactive ingredient), usually without knowing which.

•   Phase III ­- These studies, which may involve thousands of volunteers, typically last several years and compare the benefits and side effects with the standard existing treatment.

•   Phase IV - After a treatment has been approved by the FDA, Phase IV studies continue to monitor long-term benefits and side effects. They tend to involves thousands of volunteers who are all treated with the study therapy, often for several years.

Learning What to Expect

If you’re interested in participating in a clinical study, the study physician or another research professional will provide you with an informed consent form. This document provides detailed information about the study and what you should expect, including potential risks, types of treatment or procedures, reimbursement for your expenses, and the length of your commitment.

Before you agree to participate, you’ll have the opportunity to discuss your concerns and have all your questions answered. If you decide you want to participate, you’ll be asked to sign the informed consent form.

Reasons to Participate

As a study volunteer, you play an active role in your own health care and may receive new treatments for your condition while contributing to innovations that may benefit others. You may also gain access to screening tests and other healthcare services, usually at reduced or no cost.


In most (but not all) clinical studies, you may be eligible for a stipend after you have enrolled. A stipend is a fixed amount of money to compensate you for your time and travel expenses.

Coordinating Care With Your Doctor

We inform your physician that you have consented to be part of a clinical study. We then continue to keep your doctor informed as allowed by the study protocol. For routine medical care, you will continue to see your doctor. You will see the study physician for study-related care only.

Contact Us

To learn about participating in a study, call John Muir Health Clinical Research Center at (925) 674-2580 or John Muir Physician Network Clinical Research Center at (925) 687-8860.