Men who use cannabis occasionally feel stronger intoxicating effects than women with identical use habits, according to a UCLA Health study published in the journal Neuropsychopharmacology, Fox News reported.
The research included 44 healthy adults aged 21 to 55. Participants were split evenly between men and women and divided by how frequently they used cannabis.
Each participant completed three separate smoking sessions without knowing which version they received. They smoked a placebo, cannabis with a lower THC level, or cannabis with a higher THC level.
The female participants did not use hormonal birth control, and researchers scheduled testing during the same phase of their menstrual cycle, according to UA.News.
Men who used cannabis occasionally reported feeling more high, sedated, and impaired than women with similar habits. They also reported more anxiety and other unpleasant effects.
Their heart rates rose significantly after smoking active cannabis, making them the only group with that physiological response, News-Medical reported.
Blood THC levels did not explain the difference. Men and women in the occasional-use group reached similar peak THC levels despite the reported disparity in effects, Legal Reader noted.
The pattern shifted among regular users. Men and women who used cannabis frequently responded to active cannabis in similar ways.
Frequent users across both genders were more likely to state they liked the effects, wanted to use cannabis again, and chose to take more during the study.
Men who used frequently tended to have the highest blood THC levels in the study, yet they reported fewer effects than men who used the drug only occasionally.
The findings challenge earlier research suggesting women are more sensitive to cannabis effects. Dr. Ziva Cooper, director of the UCLA Center for Cannabis and Cannabinoids, explained that previous assumptions stemmed largely from animal studies or human trials that pooled mixed data.
When we designed a study to look at sex and frequency of use at the same time, and controlled for hormones, the picture changed,
Dr. Cooper said in a press release.
Lead author Dr. Stephanie Lake noted that personal history and biological sex both shape how the human body processes the drug.
Studying both together is key to understanding who is most at risk of higher-risk, unpleasant or beneficial experiences from cannabis,
Dr. Lake said in the release.
The research team acknowledged several limitations, including a small sample size of 44 participants. Several findings involving occasional male users stemmed from exploratory analyses and require confirmation in larger trials.
The cannabis used in the experiment contained 4% or 10% THC. That potency is lower than many products sold commercially today, which commonly feature THC concentrations of 20% or higher.
Blood tests showed that men and women who used cannabis occasionally reached similar peak THC levels during the experiment. Despite these comparable levels, the men reported feeling significantly more high, sedated, and impaired than the women.
Researchers ensured that female participants were not using hormonal birth control. They also scheduled all experimental testing sessions during the exact same phase of each participant’s menstrual cycle.
Participants smoked cannabis containing 4% or 10% THC, alongside a placebo. Study authors noted that these experimental strengths are weaker than many commercial cannabis products currently sold, which often exceed 20% THC.