Quirks & Quarks

Lab weed is weak and it's a research problem

The THC content of weed bought in stores or on the street is higher than lab weed and researchers think lab studies don't reflect reality.
MediJean lab manager Abdul Ahad displays marijuana leaf tissue, left, and plant callus, right, which a plant would grow from, in the research and tissue culture development lab at the medical marijuana facility in Richmond, B.C. (Darryl Dyck/Canadian Press)

This interview first aired in December, 2016.

As we here in Canada continue our slow, steady march towards legalization, a lot of the discussion has centred on the legal age limit to purchase marijuana.

The government task force recommended it should be 18 years old. That's despite the fact that the Canadian Medical Association recommended that the age limit should be 21. The worry is the effect marijuana is known to have on developing brains.

This will soon become a more familiar sight in public places in Canada. (Erika Schultz/The Seattle Times/AP)

The problem with this entire question is the science behind it.

A new study by a group of scientists in Colorado suggests there are huge, gaping holes in what we know about the actual effects of marijuana on the brain. The reason? Scientists conducting research in federally funded U.S. labs are only allowed to use weak marijuana provided by the National Institute of Drug Abuse. 

With an average potency of just over five per cent THC, that's a far cry from what people can buy in states where it's legally available for recreational use.

People can walk into almost any cannabis store and buy marijuana strains that can contain THC concentration of up to 30 per cent. And that's not even counting the refined marijuana that makes it into patches, edibles, and "dabs" that can contain up to 95 per cent THC. 

Has enough scientific research been done on marijuana to legalize it in Canada? (Seth Perlman/The Associated Press)

Dr. Cinnamon Bidwell, an assistant professor in the University of Colorado, Boulder's Institute of Cognitive Science, is one of the co-authors of the new paper. She says it's not only the concentration difference between what's commercially available on the market and what's provided by NIDA for scientific lab research that's concerning.

The diversity of active compounds in marijuana, such as THC and CBD, is also much different in the lab than it is on the streets. That, she says, is going to affect the conclusions that scientists can make about the true adverse effects and potential benefits of street legal weed.


According to Dr. Steven Laviolette from University of Western Ontario's Schulich School of Medicine who studies the effects of marijuana on people here in Canada, he says this issue in the USA is worrisome.

REUTERS/Ueslei Marcelino (Ueslei Marcelino/Reuters)

"It's very problematic because it basically ties the hands of clinicians in terms of being able to run full scale clinical trials and really sort of testing the water in terms of what formulations of medical marijuana are acceptable, which ones have more risks associated with them, which ones may have clinical benefits, which ones may pose risks under certain circumstances." 

"So yeah, there's a potentially very large knowledge gap if the U.S. research community doesn't have access to a full range of different marijuana formulations. That's really going to impede progress in terms of the clinical research. And that's really what's so desperately needed right now because we're really sort of entering into a wild frontier." 

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