An Edmonton medical cannabis consumer is concerned about quality control in the industry, after she experienced unexpected side effects from familiar strains of cannabis she received from two licensed producers.

But Health Canada, doctors and industry insiders say producers face some of the most strict regulations in the world, and say Canada's legal cannabis is safe.

Joan Kapuscinski​ has chronic pain due to fibromyalgia and insomnia. Before she started consuming cannabis a year and a half ago, she was sleeping just an hour at a time.

Kapuscinski, 60, was initially reluctant to try cannabis. But she had negative side effects from pharmaceutical drugs.

"I'm not looking to get high, I'm looking to feel better," she said.

She bought her first batch of dried cannabis in July 2017 from Alberta-based producer Aurora. She chose an indica strain — a type of cannabis that generally provides a sense of body relaxation — called Snow Globe. The concentration of THC, the component that makes a consumer feel high, was around 21 per cent.

She vaporized a pinch of it each night before bed, and said the effects were "like a miracle."

"It was relaxing and the pain went away. And I slept for like six hours straight," she said. "I woke up in the morning, no hangover, just feeling fine. It really worked."

Kapuscinski​ continued ordering the same strain for months with no issues, until she received her third order. She vaped a small amount, and her mind started racing.

"I couldn't even catch up to my thoughts, and I went to bed and I was just vibrating," she said. "Seriously, I couldn't even finish a thought. It was crazy."

Kapuscinski switched to another indica strain with a THC concentration of about 25 per cent from Tilray, another Canadian producer. She had no issues with it until her fourth order arrived.

The small green flowers didn't look, smell or taste like the same cannabis she had ordered before. They were dry, didn't have the small orange hairs she'd seen in previous batches, and it didn't give her the same instant relief. After eight days of using it, she was pacing, wringing her hands, and felt agitated and confused.

She was concerned she may have received a sativa strain — which tend to have more of an energizing effect — instead of the indica she had ordered.

She contacted Tilray and was told to send them a picture of the cannabis. She received a call back from the company confirming she received what she had ordered. Kapuscinski did not want to continue consuming the cannabis, but was told she could not return an opened package.

Kapuscinski is convinced the wrong cannabis order made it into the container.

"I'm afraid to order again, because what am I going to get this time? I don't know," she said. "So I have nothing, I've had nothing for quite a while now."

Kapuscinski was concerned she may have received a sativa strain — which tend to have more of an energizing effect — instead of the indica she had ordered. (Suppled/Joan Kapuscinski)

Slim chance of mislabeled cannabis, consultant says

The possibility that Kapuscinski received a mislabelled product is nearly impossible, said Mathew Columbro, president and co-founder of Vindica Cannabis Corporation, a Canadian company that works on licence application consultations for producers.

Tilray and Aurora are not among his clients.

Health Canada's regulations for producers are extremely strict.

Everything from soil, temperature, humidity levels, nutrients and lighting is tightly regulated. Standard operating procedures dictate that every stage of cultivation, harvesting, processing and packaging is programmed and tracked electronically, Columbro said.

These procedures need to be replicated at every step, every time, and each producer has someone in charge of overseeing this process.

A sample of each harvest is also sent to a third-party lab to test for THC and CBD levels in the cannabis, as well as for any contaminants, bacteria or mould. These labs are licensed by Health Canada specifically to handle cannabis.

All these systems are meant to eliminate human error, Columbro said.

"They're really looking at every single aspect so that Health Canada knows exactly what was grown and how much of it you have for sale, but also for the consistency of the product and to make sure mislabelling doesn't happen," he said.

"The wine and alcohol industry is not even close to being regulated as heavily as cannabis is. In terms of the safety of the product, I think we're in a really good place."

The wine and alcohol industry is not even close to being regulated as heavily as cannabis is. In terms of the safety of the product, I think we're in a really good place. - Mathew Columbro, Vindica Cannabis Corporation

There are always going to be challenges in maintaining consistency with cannabis because it is a plant, Columbro said. There are factors that can't be completely controlled that could have an effect on the final product.

But if it was a mistake with the cannabis itself or the labelling of the product, there would have been "hundreds or thousands" of incorrect orders, he said.

In a statement to CBC News, Health Canada spokeswoman Tammy Jarbeau said the production of cannabis is subject to some of the most "stringent requirements in the world" meant to protect the health and safety of Canadians.

"These standards and other requirements are backed by rigorous compliance and enforcement by Health Canada, including frequent unannounced inspections where inspectors verify adherence to the regulations," Jarbeau said.

Consumers who are concerned about product quality can contact Health Canada at cannabis@canada.ca.

Producers are not only held accountable by Health Canada, but by consumers and shareholders, so it's in their best interest to ensure cannabis production remains consistent, Columbro said.

In an emailed statement to CBC News, Tilray spokeswoman Chrissy Roebuck said the company operates in compliance with all Health Canada regulations and products undergo "rigorous" quality control testing before being sent to patients.

"Due to the agricultural nature of the product and raw materials used during cultivation, patients may perceive slight variability in final product from different harvests. Ultimately, any appeared variability does not affect efficacy, quality or patient safety," she said.

In an emailed statement, Aurora spokeswoman Heather MacGregor said the producer had not received any feedback from patients with concerns similar to Kapuscinski's.

"I'm afraid to order again, because what am I going to get this time? I don't know," Kapuscinski said. (Supplied/Joan Kapuscinski)

'There are sometimes reactions that we can't explain'

Because cannabis is a plant product, the levels of THC and CBD can't possibly be controlled as closely as that of pharmaceuticals produced in a lab, said Dr. Peter Lin, a Toronto-based family doctor and a director of the Canadian Heart Research Centre.

In terms of quality control and efforts to replicate conditions for each batch of cannabis produced, Lin said licensed producers appear to be doing everything right.

He expects the industry to even produce more consistent product as it expands due to legalization.

"Now that we have a regulated sort of system where the producers are known and they're following all these rules of good manufacturing, I think this is now making it even safer, in our minds," he said.

There could be small variations between plants of the same strain that could affect the concentrations of chemicals within the plant, Lin said. The potency of cannabis has also generally gone up "quite a bit" since the 1960s, he added.

These factors could lead to unanticipated effects on those who consume cannabis, he said.

Regular cannabis users could also develop a tolerance, Lin said, meaning they would have to consume more of it to experience the same effects.

In Kapuscinski's case, Lin said it is possible she consumed a different type of cannabis than what she believed she had purchased. Or the unexpected side effects could be due to the amount she consumed, or the method in which she consumed it, he said.

Lin suggests cannabis consumers first sample a small amount of their purchase to see how it will affect them.

"Just like in prescription medications, there are sometimes reactions that we can't explain, and that's why we report those back to the government," Lin said.

"Are we going to avoid every kind of situation like this? No, but I think this is a lot better than if we had many different people producing and maybe not following all the rules."