Just 1 in 7 cannabis products sold at Colorado dispensaries include all required warning labels , and more than half of flower , or bud, products misrepresent THC levels, according to new University of Colorado Boulder research.
The study reveals good news too: Almost all products include the required warning that they contain THC, and concentrate labels tend to be accurately labeled for potency.
"Consumers use labels to decide what to purchase and how much to use, and there are safety concerns with using cannabis," said senior author Cinnamon Bidwell, associate professor in the Department of Psychology and Neuroscience. "As accessibility and rates of use increase, it's imperative that products have clear, consistent and standardized labels."
In 2012, Colorado became the first U.S. state to legalize recreational cannabis. Since then, use has soared to 1 in 4 adults nationwide. At least 24 states now allow retail sales, and many have looked to Colorado for labeling guidance.
Colorado's Marijuana Enforcement Division (MED) mandates that several things be on the label, including: a universal symbol indicating the product contains tetrahydrocannabinol (THC); driving and pregnancy warnings; an expiration or "best by" date; recommended storage conditions; and THC potency information.
Bidwell, whose CUChange lab is a national leader in cannabis research, set out to determine whether retailers are complying.
Under federal law, university scientists are not allowed to handle cannabis for research, so the team collaborated with industry partner MedPharm Holdings LLC for a series of studies.
For one study, a secret shopper from MedPharm traveled to 52 dispensaries across the state and purchased 480 products, ranging from pre-rolled joints to loose bud to high-potency concentrates. Edibles and medicinal cannabis were not included.
"Unfortunately, when it came to warning labels, compliance overall was not great, and when it came to flower, it was pretty abysmal," said Grace Macdonald, a professional research assistant at CUChange and first author on the study, published in the Journal of Cannabis Research .
Macdonald's study found that just 14% of sampled products met all labeling requirements. Concentrates were significantly more likely to comply, with 31% containing all labels. Only 2% of flower products were labeled properly.
On the upside, 99.2% of the product labeling contained the universal THC symbol, and 97.5% contained the driving and pregnancy warnings.
"That's one place where our studies found that the system is working right," said Bidwell.
Does weed go bad?
Just as it's important for shoppers to know how long a jug of milk can sit in their refrigerator before it's not ideal to drink anymore, it's important for cannabis users to know how soon they should use their product and how to store it, said Bidwell.
"THC can degrade, particularly when exposed to light or heat or oxygen. Cannabis flower can also dry out, affecting its quality, and improper storage conditions can increase the risk of microbial growth," Bidwell said. "That's all a concern."
The state requires that, the use-by date for cannabis "shall not be longer than nine months from the harvest or production date."
Yet less than half of sampled products contained expiration or "best by" dates and only 17% included required ideal storage conditions.
That joint may not be as strong as it says it is
In a previous study , the team reported that nearly half of cannabis flower products are inaccurately labeled when it comes to potency, with most showing they contain more THC than they do. In contrast, labels on concentrates tend to be accurate, with 96% shown to match what's inside.
"These high-potency products are kind of considered the Wild West of the legal cannabis market," said Bidwell. "To at least know that the potencies reflected on the labels match what is inside is reassuring."
In a new, follow-up study, the team collected 265 new samples of flower products from 59 dispensaries. As in the first study, only half were accurately labeled for THC content.
Some products were worse offenders than others.
Joints, pre-rolled at the dispensary, were the most common violators, with 60% of samples containing less THC than they said they did (20% less on average).
Products prepared or packaged at dispensaries tended to show greater labeling discrepancies than prepackaged flower products.
More than half of cannabis sales come from flower, and joints tend to be popular among infrequent or less experienced users. Inaccurate labeling threatens both consumer trust and public health, said study co-author Jonathon Lisano, a research scientist at CUChange.
"When products contain more THC than their labels indicate, consumers may unknowingly receive higher amounts, potentially increasing the risk of adverse effects such as anxiety, paranoia or over-intoxication," said Lisano. "When products contain less THC than advertised, consumers may not be getting what they paid for."
The authors hope their findings encourage regulators to look more closely at cannabis labels and inspire the industry to do more to assure the labels on their products are accurate.
The takeaway for consumers? You can't always trust the label.
