FRIDAY, Jan. 16, 2026 (HealthDay News) -- Among men, but not women, with cannabis use disorder (CUD) seeking treatment, varenicline with medical management results in decreased cannabis use, according to a study published online Jan. 15 in Addiction.
Aimee L. McRae-Clark, Pharm.D., from the Medical University of South Carolina in Charleston, and colleagues conducted a phase 2, randomized, placebo-controlled trial in two outpatient research clinics to examine the efficacy of varenicline with medical management for reducing cannabis use in treatment-seeking individuals with CUD. A total of 174 participants were randomly assigned to either varenicline (titrated to goal dose of 1 mg twice daily) or placebo for 12 weeks (90 and 84 individuals, respectively) stratified by smoking status and sex.
The researchers found that during weeks 6 to 12, there was no main effect of treatment on reduction of total number of cannabis use sessions. However, there was a significant treatment-by-sex interaction, with a significant effect of varenicline on reduction of cannabis use sessions per week among men, but not women (between-group differences, 4.2 and −1.4, respectively).
"Our study found that varenicline, a drug that helps people to reduce or stop smoking, may be effective at reducing cannabis use as well, but only for men," McRae-Clark said in a statement. "Our next step is to further explore varenicline for cannabis use disorder, using a larger sample size of women, to better understand this sex difference in the treatment outcome."
Two authors disclosed ties to the pharmaceutical industry.