Colorado weed labels may be overselling the high, study finds
Add Axios as your preferred source to
see more of our stories on Google.
Illustration: Aïda Amer/Axios
A lot of the pot that people purchase may not be as potent as labels claim, according to a new, first-of-its-kind study.
Why it matters: Consumers — especially medical patients and new users — rely on potency labels to dose safely. But the numbers on the package often don't match what's inside, eroding trust in the industry.
The big picture: A University of Colorado Boulder study published this month in Scientific Reports found that nearly half of cannabis flower products, like loose buds and pre-rolls, overstated their THC content.
- Some gaps were significant. One strain labeled 24% THC actually clocked in at just 16%. On average, however, the discrepancy between the advertised and actual THC content was about 2%.
- Labels on concentrates, like oils and waxes, were mostly accurate, with 96% matching their stated claims.
How it works: All cannabis products sold in Colorado must be lab-tested for potency by state-accredited facilities before hitting shelves.
- Flower is trickier to test than concentrates, the researchers noted, because the plant material is naturally variable.
- Concentrates, made from uniform oils, are more straightforward to analyze.
Yes, but: Research in other states has found that some labs inflate THC levels, possibly to boost sales from consumers seeking stronger products, which tend to be pricier.
By the numbers: Researchers at CU Boulder and MedPharm Research tested 277 cannabis products from 52 dispensaries across 19 Colorado counties.
- About 44% of the flower products tested missed Colorado's accuracy threshold.
- Concentrates had an average of 71% THC, while flower hovered around 21%.
Context: In the 1980s, average THC content was just 8%.
Between the lines: The study also looked at other cannabinoids — like CBG and CBGA, which have been shown to have potential anti-anxiety or anti-inflammatory benefits — and found they showed up more often than CBD.
- But 84% of products didn't mention them on the label at all.
What they're saying: "Focusing on THC on the label can actually do a disservice for consumers," the study's senior author, Cinnamon Bidwell, co-director of CU Boulder's Center for Health and Neuroscience, Genes and Environment, said in a statement. "Our data suggests that multiple other cannabinoids should also be reported."
What's next: Researchers plan to audit labels for cannabis edibles with the goal of guiding regulations in Colorado and other states where cannabis is legal.