The Current

After 20 years of medical cannabis, gaps in product testing leave some Canadians feeling like guinea pigs

Many Canadians use medical cannabis products, but not all of those products have been studied for their safety and efficacy. More than 200 scientists and clinicians have signed an open letter calling on Health Canada to change that.

Open letter calls on Health Canada to remove barriers to testing products

According to Health Canada, 321,539 Canadians had active medical cannabis authorizations at the end of last year. That includes the use of products designed to be inhaled, applied as topical creams, or eaten. (Victor Moussa/Shutterstock)

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Rebecca Zak hoped a prescription for medical cannabis would help with her insomnia, but the need to experiment with dosage levels left her feeling like "her own guinea pig."

"I was lying there, just full body buzz in the middle of the night," said Zak, from Dundas, Ont.

"I didn't know, is this what I'm supposed to be looking for, is this working? So there was a lot of confusion for me," she told The Current's Matt Galloway.

Zak asked her doctor for the cannabis oil prescription. Her physician advised her to start with a small dose and increase incrementally. When the first prescription didn't work, she tried a stronger product, but this brought some "uncomfortable side effects" — and still no end to her insomnia. 

Rebecca Zak tried medical cannabis for her insomnia, but found that it didn't help her sleeplessness. (Submitted by Rebecca Zak)

According to Health Canada, 321,539 Canadians had active medical cannabis authorizations in December 2020. Researchers suggest that number could be far higher because not all people who use the drug medicinally seek medical authorization.

Despite medical cannabis being legal in Canada for 20 years, cannabis researcher James MacKillop said not enough is known about the efficacy or safety of the many products available.

"There's not a lot of guidance from either physicians or so-called cannabis professionals because there isn't good evidence to base that on," said MacKillop, director of the Michael G. DeGroote Centre for Medicinal Cannabis Research at McMaster University.

Without definitive research, MacKillop worries that "patients may be delaying or ultimately not accessing evidence-based treatments, if they're using products that are ultimately not shown to be effective."

Last month, he was one of more than 200 scientists and clinicians who signed an open letter asking Health Canada to remove barriers to that kind of research. 

"There is an urgent need for randomized controlled trials (RCTs) evaluating the effectiveness and safety of the numerous medical cannabis products currently available to patients in Canada," the letter said.

In Canada, cannabis products are made to safety standards akin to food or agricultural products, but not to the same standard as pharmaceuticals, which is the bar that products must meet to qualify for clinical trials.

"The same products that are approved for manufacture and sale by Health Canada don't meet their standards for being studied in trials," MacKillop said.

Physicians are wary of giving guidance on the use of medical cannabis because many products have not undergone clinical trials, says James MacKillop, director at the Michael G. DeGroote Centre for Medicinal Cannabis Research at McMaster University. (CBC)

In a statement to The Current, Health Canada said it is drafting a response to the open letter, but that its "clinical trial regulations [are] in alignment with international standards" and "aimed at protecting the safety of clinical trial participants and the integrity of the data generated." 

As a patient, Zak thinks more research into the efficacy of medical cannabis could have saved her "time and money and discomfort."

She's since found alternative relief from her insomnia — reading in the bathtub. 

CBC ARCHIVES | Canadians get option of medical cannabis in 2001:

Medicinal marijuana legalized in Canada

22 years ago
Duration 2:48
Today Canadians can apply for the right to possess and grow marijuana. And soon they may be able to buy it from the government.

Court approval created 'grey area'

Canada began allowing marijuana for medicinal use in 2001 to alleviate suffering for people with terminal or chronic conditions.

But the nature of that approval is part of the "disconnect that's really tripping up a lot of researchers nationwide," MacKillop said.

"It wasn't approved by Health Canada as a specific medication for a specific indication or condition. It was approved by the courts for people to have access to it," he told Galloway.

"Now there are dozens of licensed producers who have products that people are using for many different conditions, not just the conditions that the legal cases were based on."

MacKillop said that creates a "grey area" where licences for clinical trials are hard to secure from Health Canada, even if researchers have already secured funding for peer-reviewed trials.

Globally there are 218 ongoing registered clinical trials involving medical cannabis, including 18 underway in Canada, according to, a U.S. government database.

MacKillop said there is "moderate" evidence cannabis can help with pain and some other conditions, such as multiple sclerosis.

But for conditions such as anxiety, depression, and PTSD, he said "the evidence ranges from non-existent to actually negative." 

Barriers to research are jeopardizing the potential benefits that Canada could reap from legalizing cannabis before many other countries, says George Smitherman, president and CEO of the Cannabis Council of Canada. (Submitted by George Smitherman)

Barriers hurt Canada's industry, research

Cannabis producers are "fully aligned" with researchers calling for more trials, said George Smitherman, president and CEO of the Cannabis Council of Canada (C3), a national industry association.

He thinks that research would ultimately benefit consumers.

"I think this is really … driven by the desire to see medicinal cannabis more effectively oriented toward addressing people's ailments," he told The Current.

Smitherman, who previously served as a Liberal health minister in Ontario, said barriers to cannabis research are jeopardizing the potential benefits that Canada could reap from legalizing it before many other countries.

"We're really setting ourselves back and missing out on tremendous opportunities to better inform good, appropriate use of cannabis," he said.

Smitherman said his organization, which represents about half the cannabis being produced and sold in Canada, has been lobbying Health Canada for change for months. He said the regulator has responded with incremental changes.

We're really setting ourselves back and missing out on tremendous opportunities to better inform good, appropriate use of cannabis- George Smitherman

In September, Health Canada published clarifications around the requirements for conducting clinical research with cannabis. In its statement to The Current, the regulator said it subsequently "heard from stakeholders that more flexibility is necessary to facilitate cannabis research in Canada," and it's working to update the clarification.

Smitherman said it will take more than "a few more words of clarification" to solve the problem.

"It's really important to impress upon Health Canada that we want to see Canadian medical cannabis research reaffirmed as a priority for the government, and for Canada to have the ambition to re-establish itself as a global leader," he said.

B.C. woman used cannabis in surgery recovery

Aly Benson has been using cannabis as a medical treatment for six years. She thinks her everyday life would be "very, very painful" without it.

The Abbotsford, B.C., resident initially started using medical cannabis creams to help with a shoulder injury. More recently she has experienced sciatica, which brings on numbness and muscle spasms. She later used CBD bath bombs to reduce the inflammation, and help with mobility.

"Not being able to walk actually turned into, 'Hey, let's go for a little bit of a 10-kilometre walk,'" said Benson, who works at a Toronto-based cannabis e-commerce company. She also volunteers with the patient advisory board of Medical Cannabis Canada, a non-profit patient advocacy organization.

Aly Benson has been using medical cannabis for six years. (Submitted by Aly Benson)

Benson says she uses a variety of products — in topical, edible and inhalable forms — to help with the old injury, as well as anxiety and depression. She also recently had spinal surgery and chose to forgo opioids. She managed her recovery with medical cannabis instead, researching the dosage and treatment regime herself. It included some physio and massage therapy.

While her recovery has gone well, she said having greater guidance on dosage would be helpful, as well as clearer information on the effects of different products and how they compare.

In 2019, researchers at McMaster University published a review of almost three decades' worth of data on the use of cannabis for pain management, and whether it is associated with reduced opioid use. It found no consensus across the research

MacKillop said Benson's story shows why "people believe there's so much promise and why, indeed, we believe that medical cannabis needs to be studied more extensively."

MacKillop worries about addiction issues, saying that 'cannabis use disorder is not all that common, but it is a real thing.' (Jack Guez/AFP/Getty Images)

Risk of addiction

He worries that people may come to rely on medical cannabis products without evidence that they're effective. And habitual use could pose new problems.

Neuroscientist Sarah Konefal says that it's important to know that people can get addicted to cannabis. She recently told CBC's The Dose that cannabis use disorder, while uncommon, is one of the biggest risks associated with marijuana use.

Signs of cannabis use disorder can include using more cannabis than intended, trying unsuccessfully to control cannabis use and usage impacting other areas of your life, said Konefal, a research and policy analyst with Canadian Centre on Substance Use and Addiction.

MacKillop is also particularly worried about implications for mental health.

"My fear is that people who are vulnerable, with mental health conditions, will see this as a possible miracle cure," he said.

"And it may be that, unfortunately, the evidence ultimately won't support that."

Written by Padraig Moran, with files from CBC Radio. Produced by Ryan Chatterjee.

Hear full episodes of The Current on CBC Listen, our free audio streaming service.


  • An earlier version of this story stated that Aly Benson initially tried medical cannabis in the form of a CBD bath bomb. In fact, she first used a medical cannabis cream, and used the bath bombs to help with a later ailment.
    May 18, 2021 5:20 PM ET

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