Marijuana effects differ between men and women who use the drug occasionally, according to new research from UCLA Health. Men who used cannabis occasionally reported feeling more high, sedated and impaired than women with similar use habits, even though blood tests showed similar levels of THC, the main chemical behind the drug’s intoxicating effects. The men also reported more unpleasant effects, including anxiety, and were the only group whose heart rate rose significantly after using active cannabis. The marijuana effects study was published in the journal Neuropsychopharmacology.
The marijuana effects experiment enrolled 44 healthy adults between the ages of 21 and 55, split evenly between men and women and grouped by how often they used cannabis. In three separate sessions, each participant smoked a placebo cigarette, a lower THC cigarette and a higher THC cigarette in random order, without knowing which they had received. The cannabis contained 4 percent or 10 percent THC, which the researchers noted is weaker than many products sold today, where THC levels are commonly 20 percent or higher. Women in the study were not using hormonal birth control and were tested during the same phase of their menstrual cycle.
Marijuana effects strongest in occasional male users
Marijuana effects were strongest in men who used the drug occasionally. They reported feeling more high, more sedated and more impaired than anyone else in the study, along with more unpleasant effects such as anxiety. They were the only group whose heart rate rose significantly after smoking active cannabis. Women who used cannabis occasionally did not show the same heightened response, even though their blood THC levels were about the same as the men’s. The findings run counter to earlier research suggesting women may be more sensitive to cannabis, an idea based largely on animal studies.
Marijuana effects among frequent users were much more similar, whatever their sex. Men who used cannabis frequently tended to have the highest THC levels in their blood, yet they reported fewer effects than men who used it occasionally, a sign of tolerance. Sex alone did not predict who felt the strongest effects: the pattern depended on sex and frequency of use together. Dr. Stephanie Lake, the study’s lead author, said sex and cannabis history both shape how people feel the drug’s effects. Dr. Ziva Cooper, the principal investigator and director of the UCLA Center for Cannabis and Cannabinoids, led the work.
Marijuana effects and the limits of a small study
Marijuana effects in this study come with clear limits. The sample was small, with just 44 participants, and the groups split by sex and use frequency were smaller still. Several of the findings involving occasional male users came from exploratory analyses, meaning they need to be confirmed in larger studies. The study tested smoked cannabis in a lab, not edibles or high potency products, and the effects measured were short term. The research was funded by the United States National Institute on Drug Abuse.
The marijuana effects study is the first experiment designed to test how sex and frequency of use together shape the short term effects of smoked cannabis. It answers a call from the National Institutes of Health for research on differences between women and men, and the researchers said understanding these differences could inform how cannabis use disorder is prevented and treated. Larger studies are needed to learn whether men and women develop tolerance to cannabis differently, and how those differences could affect the risk of cannabis use disorder. Fox News Digital reported the findings on 9 November and said it had reached out to the researchers for comment.
Marijuana effects will need bigger studies before doctors can draw firm conclusions, but the UCLA results give researchers a clear place to start. Occasional male users stood out in every measure the team tracked: how high they felt, how sedated and impaired they felt, how anxious they felt, and how fast their hearts beat. Women with the same habits did not show the same response. The next step is a larger trial with the stronger products people actually buy, to see whether the pattern holds.