What You Should Know About Clinical Trials

Clinical Trials

Clinical trials help find new ways to improve health. Participating has risks and benefits you need to learn about before signing up.

Clinical trials are research studies in which ordinary people can help doctors and scientists find ways to improve health care. Each trial tries to answer questions and find better ways to prevent, diagnose or treat diseases and conditions.

Most clinical trials are studies that compare new or existing drugs, products or therapies. Many will evaluate medications or treatments that have not been tested before. The trials try to find whether one treatment works as well or better. These studies must follow a pre-defined plan (protocol) that outlines:

  • Who may participate
  • Schedules of tests, procedures, drugs and dosages
  • Length of study

Clinical trial types

Different kinds of clinical trials include:

  • Treatment. New treatments or combinations of existing treatments are tested to see how safe and effective they are in treating certain diseases or conditions.
  • Prevention. These look for better ways to help prevent a disease in people who have never had it or to keep it from returning.
  • Screening. These test the best ways to find a disease or condition.
  • Quality of life. These explore and measure ways to improve comfort and quality of life for people with chronic illnesses.

The protocol of all clinical trials is designed to protect the health of participants. If you take part, your health will be closely watched during and after the study. This helps to decide on the safety and effectiveness of treatment.

Federal regulations require any clinical trial in the U.S. to be approved and monitored by an Institutional Review Board (IRB). This board is composed of doctors, statisticians, advocates and others. The IRB makes sure that the clinical trial:

  • Is ethical
  • Protects the rights of study participants
  • Does not involve more risks than potential benefits

Risks and benefits

Taking part in a clinical trial involves both potential benefits and risks.


  • New drugs and procedures may have unknown side effects or risks.
  • Treatments may be less effective than current therapies or not work at all.
  • It may require more time than would a non-trial treatment. This would include trips to the study site, more treatments, hospital stays and complex drug dosages.


  • Care from top doctors
  • Access to drugs and therapies not on the market yet
  • Successful treatment or reduction of symptoms in some cases

How you’re protected

Ethical and legal codes that govern medical practice are the same rules that apply to clinical trials. Most clinical research is federally regulated with safeguards meant to protect participants.

Regulations require clinical trial teams to thoroughly inform you before you sign on. This is known as informed consent. You should be told about:

  • Treatments
  • Tests
  • Possible benefits and risks

As the trial progresses, researchers often report results at meetings, in medical journals and to government agencies. No names are mentioned.

Signing up

If you think that a clinical trial is right for you, be sure to ask questions until you are sure that you are fully informed. To ensure that trial results are reliable, you need to follow instructions carefully. You can ask the study team questions at any point. You can also leave a study whenever you want – before it starts, during the study or in its follow-up period.

To find a trial, you may want to start with the Web site ClinicalTrials.gov. The National Institutes for Health maintains this site as a registry of trials in the U.S. and worldwide. At any one time it has details on over 80,000 trials in about 170 countries.

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