Most edible medical marijuana products deliver significantly more or less wallop—mostly less—than their labels promise, according to new research.
The results suggest some patients who consume marijuana-laced products to treat disease or control symptoms could be unintentionally overdosing on the drug’s primary psychoactive ingredient. Mislabeled brownies, cookies, iced teas, or sodas, may cheat many more.
“If this study is representative of the medical cannabis market, we may have hundreds of thousands of patients buying cannabis products that are mislabeled,” says experimental psychologist Ryan Vandrey, associate professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine.
BUYER BEWARE
Vandrey is lead author of a report on the small proof-of-concept study in the Journal of the American Medical Association. The journal also published a separate review of clinical trials of medical marijuana; that study found little scientific evidence to support use of the drug for most of the conditions for which it is prescribed.
Vandrey’s study find that the vast majority of edible cannabis products sold in a small sample of medical marijuana dispensaries carried labels that overstated or understated the amount of delta-9-tetrahydrocannabinol, or THC.
Calling for better regulation and government oversight, Vandrey and his colleagues say patients who consume underlabeled products—with more THC than is stated on the label—could suffer from overdosing side effects, including extreme anxiety and psychotic reactions. Patients purchasing products that are over-labeled are not getting what they paid for, he adds.
“Caveat emptor,” or “let the buyer beware,” is “just not right” for the sale of medical marijuana, he says.
13 PERCENT HAD ACCURATE LABELS
A total of 23 states and the District of Columbia permit the sale or use of medical marijuana to treat disease or improve symptoms. Users of edible forms consume it to reduce vomiting during chemotherapy, improve appetite, or treat pain or muscle spasms. Four states and Washington, DC, permit marijuana sale and use for recreational purposes, though the drug remains illegal under federal law.
Vandrey teamed with an independent laboratory and collected 75 different edible cannabis products—baked goods, beverages, and candy or chocolates—representing 47 different brands. The products were legally purchased from three medical dispensaries in each of three cities: Seattle, San Francisco, and Los Angeles.
“Those cities were chosen based on the location of the labs” in California and Washington, says Vandrey, “because you can’t transport these products across state lines legally.”
When lab analysis of THC content differed from the product label by more than 10 percent, the researchers categorized a product as either under-labeled or over-labeled. Only 13 of the 75 products (17 percent) were accurately labeled.
Some 17 products (23 percent) had more THC than advertised. Even more—45 products (60 percent)—were over-labeled, meaning patients purchasing those products for their THC content are not getting the dose they expected.
“We didn’t have a guess as to how many products would have inaccurate labels,” Vandrey says, “but I was surprised it was so many.”
BETTER REGULATION?
The team also tested the products for cannabidiol, or CBD, another active ingredient in cannabis believed to have medical benefit, including helping to reduce side effects of THC.
Laboratory testing showed 44 products (59 percent) had detectible levels of CBD, but the average ratio of THC to CBD was 36-1. Only one product had a 1-1 ratio, which some research suggests is associated with fewer side effects and improved clinical benefit.
“A lot of dispensary owners and medical cannabis proponents make a big case about how therapeutically beneficial CBD is,” says Vandrey, “but our testing indicates that a lot of what’s available in the edible cannabis market may have very little CBD.”
In the absence of federal regulation, says Vandrey, “the states that have medical marijuana laws need to account for the quality and testing of medical marijuana products sold to their residents.”
Other authors of the paper are from The Werc Shop laboratory and the University of Pennsylvania. The Johns Hopkins University School of Medicine and The Werc Shop laboratory, which provided testing and associated costs, supported the work.
Fuente: www.futurity.org
