Occasional Cannabis Users: Men Feel Stronger Effects Than Women, Study Finds
A UCLA Health study of 44 healthy adults found occasional male cannabis users felt stronger effects than occasional female users. Among frequent users, men and women responded similarly. Researchers say the small trial needs confirmation in larger studies.
Men who use cannabis occasionally may feel stronger effects than women with similar habits, according to a UCLA Health study of 44 healthy adults published in the journal Neuropsychopharmacology. The finding is a reminder that how often people use the drug may matter as much as whether they are men or women.
Participants were between the ages of 21 and 55 and split evenly between men and women. Researchers sorted them into frequent and occasional cannabis users.
Each person took part in three sessions. They smoked cannabis with no THC, a lower amount of THC or a higher amount, and did not know which they received.
Among occasional users, men reported feeling more high, sedated and impaired than women did. They also reported more unpleasant effects, including anxiety, and their heart rates rose significantly after active cannabis.
Blood THC levels did not explain the gap. Occasional male and female users reached similar peak THC levels, even though the men described stronger effects.
The pattern changed among frequent users. Men and women in that group generally responded alike to active cannabis.
Frequent users were also more likely than occasional users to say they liked the effects, wanted to use cannabis again and chose to take more during the study. That held regardless of gender.
The results challenge earlier research suggesting women may be more sensitive to cannabis. Dr. Ziva Cooper, the study's principal investigator and director of the UCLA Center for Cannabis and Cannabinoids, said in a press release that "much of what we thought we knew about sex differences in cannabis effects came from animal research and from human studies that pooled data from different trials."
"When we designed a study to look at sex and frequency of use at the same time, and controlled for hormones, the picture changed," she added. The team accounted for menstrual cycle timing in women who were not using hormonal birth control.
The researchers acknowledged several limitations. The study was small, and several findings involving occasional male users came from exploratory analyses, which need confirmation in larger studies.
The cannabis used contained 4% or 10% THC. The researchers noted that is weaker than many products sold today, where THC levels are commonly 20% or higher.
They said larger studies are needed to learn whether men and women develop tolerance differently and how that could affect the risk of cannabis use disorder.
Lead author Dr. Stephanie Lake, also a researcher at the UCLA Center for Cannabis and Cannabinoids, said both factors count. "Studying both together is key to understanding who is most at risk of higher-risk, unpleasant or beneficial experiences from cannabis," she said.
