Study: THC Labeling for Concentrate Products More Accurate Than Flower 

A study published Tuesday in the journal Scientific Reports found just 56.7% of flower products tested within 15% of their labeled THC content, while 96% of concentrate products tested by the researchers contained within 15% of their labeled THC content. 

Researchers from the University of Colorado, Boulder, and MedPharm Holdings LLC, which operates as Bud & Mary’s, sampled 182 flower and 99 concentrate products – including 27 unique concentrate forms – from 52 Colorado dispensaries in 19 counties for the study between November 29, 2022, and October 3, 2023. Four flower products were excluded from the analysis due to misprinted or absent THC potency labeling.        

“Observed THC potency was significantly lower than labeled potency in both flower and concentrate products. Nearly all tested concentrate products met the accuracy threshold for THC content, whereas flower products frequently did not. Both product types had lower observed THC content compared to labeled values.” — “Accuracy of labeled THC potency across flower and concentrate cannabis products,” Scientific Reports, July 1, 2025    

The researchers found, for flower products, the mean labeled THC potency was 22.5% while the observed potency was 20.8%, while for concentrates, the mean labeled THC potency was 73.0% with an observed potency of 70.7%. 

The researchers note that “discrepancies between federal and state cannabis laws have resulted in varied regulation and oversight.” 

Inflated THC levels reported on cannabis product labels have long been an issue in the industry, and lawsuits have been filed against cannabis companies and laboratories in Arkansas, California, and Massachusetts. In 2020, regulators in Washington state suspended the license of Praxis Labs after finding it had falsified over 1,200 results in order to inflate THC levels. A study published last year in the Journal of Cannabis Research that analyzed 107 adult-use flower products collected at random by law enforcement in California, Oregon, and Colorado found over 70% of products fell outside of a 20% accuracy threshold for THC potency – of which all but one of the inaccurately labeled products included inflated THC levels.