A Guide to Understanding Clinical Trials

Here you will find useful information to help you understand about clinical trials and how you can take part in advancing the future of medicine.

What Is a Clinical Trial?

A clinical trial is carefully designed research that involves voluntary human participants to test the safety and effectiveness of treatments such as drugs, medical devices or behavioral interventions used to treat or prevent certain diseases.

A Clinical Trial Aims To

  • discover new treatments that work better and are less invasive than standard treatments
  • evaluate the best methods to detect and diagnose diseases
  • find ways to prevent diseases through medications, lifestyle interventions or vaccinations
  • identify ways to improve quality of life and care for patients with health conditions

What are the Different Kinds of Clinical Studies?

Research scientists perform different kinds of research for various reasons depending on questions they are trying to answer. They may do research study to look at causes or symptoms over time, look at behavioral interventions and or perform clinical trials to test treatments.

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The Phases of a Clinical Trial

Clinical trials are carried out through series of steps or phases to help researchers effectively test treatments. Below are descriptions of each of the phases:

Phase I

  • Tests for safety and dosage as primary importance to identify side effects
  • Involves small group of people (20–100)
  • It can last several months

Phase II

  • Continues to test efficacy or effectiveness of treatment and safety
  • Involves several hundreds of people (100–300) with the target disease
  • It can last several months to 2 years

Phase III

  • Tests for long term safety, confirms efficacy and compares treatment to standard therapies
  • Involves 300–3,000 patients with the target disease
  • Can last up to 4 years

Phase IV

  • Occurs after FDA approves treatment for marketing
  • Examines additional long-term safety, side effects and efficacy of the drug for extended time
  • Can last for years and involves several thousands of patients


Clinical Research -- What You Should Know

Here are a Few of the Many Advantages of Participating in a Clinical Trial:

  • First Access to Promising Treatments
  • Free and Expert Medical Care
  • Opportunity to Advance Medicine
  • Active Role in your Health

Clinical Trials and Protections of Human Subjects

There are ethical guidelines set to protect safety and rights of patients and healthy research volunteers throughout the duration of clinical trial. Multiple entities such as the FDA, institutional review board, research investigators, industry sponsors, etc. are involved.

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How are Research Participants Protected?

Important Questions to Consider Before Participating in a Clinical Trial

Before participating in a clinical trial, it is important to gather as much information as possible to understand about the study, its purpose and eligibility requirements to participate. Below are important questions to consider and discuss with your doctor and or family members before making decisions.

  • What is the purpose of the study?
  • Why do researchers believe the new treatment being tested may be effective?
  • What kinds of tests and treatments are involved?
  • What are the chances I will receive a placebo or treatment?
  • Who will be following up with me in the process?
  • What are the possible risks and benefits in the study compared to my current treatment?
  • What are the commitments for the study or how might this trial affect my daily life?
  • How long is the study?
  • How will I know that the treatment is working?

Steps you can take to participate in a research study

Check out this Infographic to learn more about the steps you can take to participate in a myasthenia gravis research study.

Is Clinical Research Right for Me?

Check out this NIH infographic to learn more about how clinical research might be right for you.