Do you ever feel like you have a weed hangover? Delta-9-tetrahydrocannabinol (THC) is the main intoxicating cannabinoid in cannabis products. While the effects of smoking weed or eating an edible are primarily felt for just a few hours, researchers are wondering if there is significant cognitive and psychomotor impairment the day after using cannabis. The recently published study “The “Next Day” Effects of Cannabis Use: A Systematic Review” reveals what they found.
This review analyzed studies where participants performed safety-sensitive tasks such as driving, flying, and neuropsychological tests more than eight hours after using cannabis. Twenty studies with over 450 participants were evaluated. Participants were administered 11mg to 26mg of THC and their performance was assessed 12 and 24 hours after treatment.
Of the 345 tests conducted across sixteen published studies, no “next day” effects of THC were observed in 209 tests. However, some of the studies did fail to demonstrate that participants were impaired after their treatment dose of THC. IT was among these lower-quality studies that “next day” effects were reported. Researchers ultimately concluded that there is little evidence to support the claim that THC can result in impairment the day after use. Of course, more research is needed to fully reject this hypothesis.
This finding is actually very poignant when it comes to considerations of workplace safety and the use of drug testing for marijuana. With the rise of cannabis legalization across the US, many employers are having to reconsider their drug testing policies. Studies like these are important because they help alleviate negative stigmas around using cannabis and demonstrate that, like responsible drinking, using cannabis responsibly is not a recreational option that negatively impacts workplace performance.
So if you feel like you have a weed hangover, it may be the case. However, despite feeling groggy it is unlikely that THC is still affecting your cognitive and psychomotor abilities. It’s more likely that you feel bad from staying up late, not hydrating enough, and fulfilling your munchies with junk food.
McCartney, D., Suraev, A., & McGregor, I. S. (2022). The “Next Day” Effects of Cannabis Use: A Systematic Review. Cannabis and cannabinoid research.
Sabine Downer is a scientist and cannabis writer with a passion for education. She has been writing for various clients in the cannabis space since 2015 and has worked in biotechnology since 2010. Along with content creation, she is also a knowledgeable resource on quality assurance, regulatory, and legal topics.