Marijuana products in Colorado have lower THC potency than advertised on labels
THC plays a significant role in consumers' decision to purchase a particular marijuana product and the price they are willing to pay. However, a study published in the PLOS One journal on April 12 revealed that the THC potency labeled on marijuana products' packaging in Colorado might be inaccurate.
Researchers from the University of Northern Colorado found that the THC potency of the majority of marijuana products analyzed and bought in Colorado's dispensaries is lower than the advertised potency on the product labels, highlighting "a lack of standardized testing protocols, limited regulatory oversight, and financial incentives to market high THC potency likely play a significant role."
The authors of this study purchased 23 marijuana flower samples from ten licensed dispensaries in Colorado, representing 12 different strains.
A third-party lab (Mile High Labs) analyzed the sample using high-performance liquid chromatography.
The findings show that 18 of 23 samples (78.26%) had a lower THC potency than the lowest value reported on the label. On average, the actual amount of THC was 14.98%, while the labeled amount was 20.27% for the low range and 24.10% for the high range.
Furthermore, 16 out of 23 samples (69.56%) had a THC potency that was more than 15% lower than the lowest reported THC potency, and 13 of those samples (56.52%) had a THC potency that was more than 30% lower than the labeled value.
When researchers assessed the highest THC potency claimed on the labels, 20 out of 23 samples (86.95%) had a THC potency more than 15% lower than the highest reported value, with 18 of those samples (78.26%) being more than 30% lower.
"Our results demonstrate that there are substantial, statistically significant differences between THC % by dry weight (hereafter THC potency) reported on consumer labels and our observed test results," the study reads.
The causes of such a discrepancy may depend on multiple factors, such as the different methods used to assess THC potency. However, the authors of this study explain that such a mislabeling might be due to the phenomenon of so-called "lab shopping," where cultivators and dispensaries partner with labs that generate the most desirable lab results to obtain higher THC potency results.
Although this study includes a small number of samples taken into consideration to assess the discrepancy over the THC potency of marijuana products, the findings confirm the results shown in other studies investigating the inflated THC potency.
"Given that increased THC and CBD potency are associated with higher prices, and that potency and price are the major factors driving sales, comparisons relative to the highest reported potency are likely more indicative of what consumers expect when making purchasing decisions," the study reads.
Mislabeling of marijuana products also occurs for CBD products. A recent study showed that almost 60% of CBD products sold in the United States have CBD content that differs from the percentage advertised on their labeling.
Regarding THC potency, two consumers sued a California marijuana company late last year because their products contained less THC potency than what was labeled on the packaging and accused the company of false advertising.
The study highlights that inflated THC potency is likely a widespread problem within the industry, and it would be necessary to conduct other studies on other US legal marijuana products with larger sample sizes to confirm this study's findings further.
"Although we have no power to change the current system, we hope highlighting this issue and educating consumers will affect the change needed to remedy inflated potency of flower products. Addressing this discrepancy will require both changes to the regulatory system and consumer awareness that reported THC potencies are frequently inflated," the study concludes.
