Clinical trials are research studies that investigate new or existing pharmaceutical treatments. Most commonly, clinical trials are used to determine whether a new drug is safe and effective, as this type of testing is required by the US Food and Drug Administration (FDA) prior to gaining approval for sale of new drugs within the United States.

Although participation in research studies is not suitable for all individuals, many individuals find that they offer a cost-free opportunity to possibly treat medical problems using leading-edge treatments not otherwise available.

Prior to entering a research study, you will be fully informed of all study procedures, possible risks and benefits of treatment, and the availability of alternative treatments, so that you can make an informed choice about the suitability of a clinical study for your particular condition.this is called the "informed consent" process.

In most research studies, the main researcher (often called the Principal Investigator) is a physician, although psychologists, nurses, laboratory technicians, clinical research coordinators and other associates also provide important study functions.

Some research studies enroll only healthy people, while others enroll only patients with particular problems or diseases. The researchers who conduct the studies establish these and other guidelines at the outset of the study in order to ensure that they will gather useful and valid results. If you meet the study’s guidelines for inclusion in the study, and do not meet any of the study's reasons for exclusion, you are eligible to join.

Many research studies test a new drug against a placebo (sometimes called a “sugar pill”), which looks just like the real drug but doesn’t contain any active ingredients. Other studies test two different drugs to see how they compare, while other studies compare different doses of the same drug to learn which dose is the most effective.  Most research studies are randomized, which means that participants are randomly assigned to one treatment or the other (for example, to take either the active drug or the placebo).

As a participant in a research study, you will never be identified by name in any study documents.  Although the FDA, Institutional Review Boards and Sponsors may have access to the medical records of study participants, federal law protects that information from being used elsewhere.

During the “informed consent” process, which occurs prior to any study-related procedure, researchers will tell you how your research materials will be handled and safeguarded. In written study documents, researchers always identify patients by their initials and assigned study numbers rather than by names.

In the United States, most research studies that involve pharmaceutical agents are sponsored by drug manufacturers. Such sponsors pay teams of investigators to conduct and oversee the studies. Researchers and sponsors negotiate many kinds of financial arrangements, and in many cases, researchers also pay patients who participate in a research study.

You are always free to leave a study for any reason. The informed consent document that you sign does not force you to remain in a study.  If you do leave a study, it is usually helpful to let the researchers know why you are leaving, although this is not required.

Although researchers make great efforts to help you complete a study, there are some occasions that require a patient to be withdrawn. For example, if a participant violates the requirements of the study by intentionally taking a restricted medication, that participant would be removed from the study.

In addition, researchers may end your participation for other reasons, including (a) changes in your health that disqualify you based upon the study’s inclusion and exclusion criteria, (b) a sponsor’s decision to end the study because enough data has been collected, or (c) the acquisition of new information that makes the study unnecessary or risky.