UConn Study Uncovers Gaps in CBD Beverage Labeling and Actual Content

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Content of the cannabinoid cannabidiol (CBD) in brewed coffee may not be as high as stated on packaging, a new experiment has found. An August 5, 2025, news release (1) from the University of Connecticut explained the results from this experiment, conducted by student Colby LeGault in the laboratory of Gerald Berkowitz, professor of horticulture in the Department of Plant Science and Landscape Architecture. LeGault tested two commercially available brands of CBD coffee, analyzing the cannabinoid content of each using high pressure liquid chromatography (HPLC).

LeGault found that the actual CBD content of the brewed coffee was 70-80% less than advertised on the packaging.

“[Almost] nothing is showing up in the end result when you brew the coffee,” stated LeGault in the news release. “We found that these companies are marketing their products as having this much CBD in it. While that may be true at some point in the process, it’s not a bioavailable form upon brewing.”

The CBD oil had been added to the coffee grounds and not the final product. The hydrophobic nature of CBD oil contributes to the difficulty in absorption though water alone, leading to the lack of cannabinoid in extraction, LeGault explained. “When it comes to coffee grounds, the CBD is there, it’s in an oil,” he stated. “But since that oil is hydrophobic, it does not bind with water, so nothing is extracted. Therefore, none of the cannabinoids are released into the water that will become your coffee.”

LeGault noted that this situation can also be seen in other CBD products, emphasizing the need for third-party lab testing and consumer protections and for ensuring consistency. He also noted inconsistency of CBD content the coffee grounds between samples.

Cannabinoid content has also been tested in a different beverage as well. A 2024 study (2), published in Journal of Agricultural and Food Chemistry, tested the cannabinoid content of cannabis tea, both with and without the addition of cream. The study tested three cannabis cultivars and more than 40 phytocannabinoids. For each cultivar, 1 g of dried cannabis flower was boiled in 250 ml of water for 10 minutes, then the cannabinoid transfer was tested using UHPLC-HRMS/MS. During steeping, 20 g of cream with 10% fat was added. “Phytocannabinoid acids were transferred generally in a higher extent compared to their counterparts; in the case of Δ9-THC, it was only in the range of 0.4–1.9% of content in the Cannabis used,” the researchers explained. “A dramatic increase of phytocannabinoids, mainly of the neutral species, occurred when cream was added during steeping, and the transfer of Δ9-THC into ‘tea’ achieved a range of 53–64%.”

Boiling water alone was not enough to decarboxylate the acidic cannabinoids, but the addition of cream increased the transfer of neutral cannabinoids and altered the safety profile, the researchers stated.

References

1. Aldrich, AZ. Down the Drain: UConn Student Researcher Discovers the Truth About Some CBD Coffee Products https://today.uconn.edu/2025/08/down-the-drain-uconn-student-researcher-discovers-the-truth-about-some-cbd-coffee-products/ (accessed August 7, 2025).
2. Maly, M.; Benes, F.; Binova, Z.; Hajslova, J. Tea Prepared from Dried Cannabis: What Do We Drink? Journal of Agricultural and Food Chemistry. 2024, 72(38) DOI: 10.1021/acs.jafc.4c05940