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Clinical trials are only possible if there are volunteers willing to participate in studies. People choose to participate in a clinical trial study for a variety of reasons. Clinical trial participation is a personal choice that is made after careful consideration of the benefits and risks.

What are clinical trials?

Clinical trials are research studies that test a drug, therapy, procedure or medical device on people. The purpose is to find out if a new treatment is safe and effective. Many treatments used today are the result of past clinical trials.

For treatment to become the standard of care, it must first go through several clinical trial phases. Early phase clinical trials ensure the new treatment is safe. Later phase clinical trials assess if the new treatment works better than the current treatment. If you take part in a clinical trial, you usually only take part in one phase of the study.

The phases for clinical trials are:

 Phase I:

  • Small group of healthy volunteers.
  • The main goal is to assess how the study treatment affects the body.
  • Determine safe dosage.
  • Identify side effects.

Phase II:

  • Approximately 100-300 volunteers who have a specific disease.
  • The main goal is to assess the effectiveness of the treatment.
  • Phase II does not use placebos (sugar pills).

Phase III:

  • Much larger group of volunteers (1,000-3,000).
  • The goal is to gather more information about the safety and effectiveness of the treatment.
  • Compare to other treatments.
  • May use a placebo (sugar pill).
  • If deemed effective, the treatment will receive approval.

Phase IV:

  • Involves thousands of volunteers.
  • After the treatment has been approved, researchers study for additional benefits, risks and uses for the treatment.

Informed consent helps you to learn about a clinical trial before you decide to participate. During this process, the physician or study coordinator will talk to you about:

  • the purpose of the clinical trial,
  • the potential risks and benefits of participating,
  • other treatment options you may have if you decide not to participate, and
  • your rights as a participant in the clinical trial.

During the informed consent process, it is important to ask questions about anything that you did not understand.

Once you receive all the information about a clinical trial, you can think about whether you want to participate. If you decide to participate, you will be asked to sign an informed consent form. When you sign this form, it shows that you have been given all the details about the trial and that you want to participate. We ask if you will let us inform your primary health-care provider that you are in the study and encourage you to talk to your primary health-care provider about the clinical trial.

Clinical trials are voluntary. You can withdraw at any time. If you decide to withdraw from the clinical trial, it will not affect the quality of the care you receive. It’s also important that you know that you may or may not directly benefit from being in a clinical trial.

How you are protected

In Newfoundland and Labrador, all clinical trials require the approval of the Health Research Ethics Board. Clinical trials follow strict regulations and must follow good clinical practices. They are closely monitored by regulatory bodies that may include Health Canada and the US Food and Drug Administration. These regulations ensure that:

  • the health of the people in the trial is protected,
  • the trials are well-designed and conducted properly by trained professionals, and
  • the trials are monitored adequately and potential side effects are reported.

Frequently asked questions

If you are interested in learning more about clinical trials or would like to inquire about clinical trial studies that are looking for participants, please click the button below to visit NLStudies Connect.

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Published on: March 4, 2026

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