Study: THC and CBD Detectable in Breath After Consuming Edibles, Even Hours Later

Published in the Journal of Analytical Toxicology, the study was conducted by scientists at the National Institute of Standards and Technology and the University of Colorado Anschutz Medical Campus. While breath testing for THC after smoking marijuana has been widely studied, this research focused on edibles—a growing segment of the legal marijuana market. Participants were given a cannabis-infused edible and then provided breath samples before ingestion and at three different time points afterward. They were assigned to one of two breath collection devices to evaluate potential differences in detection. The study revealed that while most participants did show THC in their breath after consuming the edible, the timing and concentration varied significantly.

Of the individuals studied, 19 reached their highest THC levels at 47, 92, or 180 minutes after eating the edible. However, six participants had their peak THC levels before recorded ingestion, and four showed no significant change at all. Researchers also detected five other cannabinoids in breath samples, including cannabidiol (CBD). While some participants showed parallel patterns in THC and CBD levels, others displayed divergent trends, suggesting different metabolic pathways.

The authors emphasize that although the study confirms that THC can be present in breath after consuming edibles, current testing methods face limitations. The variability among individuals and the need for a longer monitoring window underscore the challenges of using breath testing as a reliable indicator of recent edible consumption.