Clinical trials and drug safety

There is an urgent global need for COVID-19 diagnosis, treatment, mitigation or prevention options. Sponsors must apply to conduct a COVID-19 clinical trial in Canada through the Food and Drug Regulations or the interim order No. 2 for clinical trials for medical devices and drugs related to COVID-19.

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The issue

Every year, Health Canada receives hundreds of new clinical trial applications. These applications are to test new drugs (including vaccines) or new uses of approved drugs on humans. When you participate in these trials, you have a chance to take part in research that could improve your health or the health of others.

Clinical trials can be an important treatment option. However, like all drugs, the drugs used in clinical trials have possible benefits and risks. There is often less information about the safety and efficacy of a drug being studied in a clinical trial than for an authorized drug.

In Canada, pediatric patients (children and youth) can participate in clinical trials with the patient's and their parent's permission. Health Canada takes an active role in protecting the health of Canadians who take part in clinical trials, including children and youth.

There can be big differences in how a drug works in an adult and how it works in a child or youth. That is why clinical trials with children and youth are important to learn whether a drug is safe and effective for these patients.

Before you take part in a clinical trial, you should talk about the possible risks and benefits with your health care provider, as well as your family and others in your support system. This will help you to decide whether to participate in a trial.

About clinical trials for drugs

Pre-clinical studies

When researchers develop new drugs, the first tests are called pre-clinical studies. These tests are done using cells, tissue samples or animals. If the pre-clinical test results are promising, the next step is a clinical trial.

Clinical trials

Clinical trials are studies to find out whether a drug is safe and effective for people. The people who take part in trials are volunteers. They may be:


The person or organization that tests a drug is called a sponsor. Health Canada does not sponsor or conduct drug research. Sponsors of clinical trials are usually:

Clinical trial application

Before conducting a trial, the sponsor submits a clinical trial application to Health Canada. Our scientists review the application to make sure:

Clinical trials in Canada must follow Division 5 of the Food and Drugs Regulations and good clinical practices. They must:

Who else is involved

The people who carry out clinical trials are called investigators. Investigators in Canada are usually physicians. Researchers, nurses or other health professionals may also be involved in a clinical trial. Trials often have research teams and take place in hospitals, medical clinics, doctors' offices and universities.

Phases of clinical trials

Clinical trials are often done in 4 phases. Each phase has a different purpose and helps researchers answer specific questions. Some trials combine phases.

Possible benefits

When you take part in a clinical trial, you help others by moving medical research forward. Also, if you have a disease, there could be personal benefits, such as:

Possible risks

If your reason for being in a clinical trial is to get a new treatment, be aware that this may not happen. Clinical trials often compare a new drug to:

In many cases, people are not told which treatment they are getting. This is done to make sure the results are not biased. Even if you get the new drug, it may not help you. It might be less helpful than a treatment you were using before the trial. There is also a risk of serious short- or long-term side effects as the safety of an investigational drug is not as clear as an approved drug.

A clinical trial involves travel, tests and possible hospital stays, which can take up a lot of your time.

Reduce your risk

If you participate in a clinical trial, you should understand what is involved and give your consent before starting the trial.

Read the informed consent form before you decide. By understanding the benefits and the risks, you can make an informed choice about participating. It's also a good idea to talk to your family and friends. If you have questions, talk to your health care provider.

If you choose to join a clinical trial:

You have the right to quit a clinical trial at any time. If you quit, the trial's medical staff will make sure that you are taken off the medication safely.

The role of clinical trials in drug approvals

Pre-market stage

The pre-market stage consists of:

If clinical trials prove the drug's benefits are greater than its risks, the drug company will apply to Health Canada for market approval to market that drug. This application includes detailed information about the drug's safety, efficacy and quality. This information includes:

Health Canada's scientists review this information. The drug is approved for sale in Canada if:

Once approved, the new drug gets:

Post-market stage

The post-market stage involves the surveillance, inspection and investigation of a drug while it is on the market.

Ensuring safe and effective drugs

Health Canada plays an active role in making sure Canadians can get safe and effective drugs. As part of this work, we protect the health of Canadians who take part in clinical trials. We:

In some cases, inspectors visit sites where clinical trials take place to:

If there are severe side effects, we make sure that patients are checked more closely or we may stop the trial.

Health Canada also gives Canadians information about clinical trials so that they can make choices based on what they have learned.

The clinical trials database lists all of the phase 1, 2 and 3 clinical trials involving patients in Canada. It has information on the:

The Canadian Institutes of Health Research funds health research, including clinical trials.

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