Be careful what you believe when you buy edible medical marijuana. That’s the lesson of a new study that shows food infused with cannabis is often much less potent than advertised.
The study found that a majority of edible cannabis products designed for medical use are mislabeled. That makes it much more difficult for patients to know how much THC the products contain.
THC is the chemical in cannabis that gets users high. THC levels vary from strain to strain and are higher in concentrated forms of marijuana, including edibles. Strains and concentrates with especially high levels of THC are prized.
THC and CBD content misrepresented
For recreational users, an inaccurate THC count means the difference between getting high and getting really high. But for medical marijuana patients, effective treatment can depend on careful dosing. That can’t be done with misleading data.
CBD levels are also typically misrepresented, the study found. CBD is a non-intoxicating cannabinoid used to treat severe seizure disorders and other conditions. Many patients require a THC/CBD ratio of roughly 1:1, a balance that can be hard to find.
The study, published in the Journal of the American Medical Association, reports that just 17 percent of 75 tested edible products, all bought legally in three cities, were correctly labeled. The survey defined accuracy as a reported THC level within 10 percent of the actual measured level.
The study found 23 percent of the items were under-labeled, advertising less THC than they really contained. But the remaining 60 percent oversold their THC contents, reporting levels that didn’t bear out under laboratory testing.
Patients and recreational users being undersold
The patients who buy these items are getting less than they’re paying for. They’re also often getting a less effective form of treatment, especially from products that are low in both THC and CBD.
“A couple of products that were supposed to contain 100 milligrams of THC but had only two to three,” said Ryan Vandrey, lead author on the study and associate professor of psychiatry and behavioral science at Johns Hopkins University. “That was striking – these were not cheap products and were being sold as medicine.”
Medical marijuana is legal to varying degrees in 37 states, including 14 that allow only CBD preparations. Most of the study’s data came from Colorado, where pot is legal for both recreational and medical uses.
Limited research on medical marijuana
The authors of the study note that the science on medical marijuana remains scarce. Among other things, that makes it more difficult to gauge the best concentration of THC or CBD for patients. It’s easier to dose these chemicals using edibles, but even then it’s nearly impossible for patients to accurately assess the THC or CBD levels.
And underdosing isn’t the biggest danger. Many patients have limited tolerance for side effects, and too much THC can trigger panic attacks, paranoia, headaches, and other unpleasant effects. Edibles can contain substantially more THC than dried, smokeable plant matter, even without mislabeling.
Edibles are a sizeable part of the medical marijuana market. They account for 16 to 23 percent of cannabis purchases by patients, according to the study.
There are some rules in place to protect against mislabeling, but few that specifically address medical marijuana. Colorado passed regulations last year requiring potency testing, but only on the recreational cannabis market.
New laws in the state now require independent testing and certification for weed-infused products sold as medicine. Washington State requires similar testing of THC and CBD levels in MMJ.