Exploring the Association between Cannabis Use and Testosterone Levels in Men Receiving Methadone Maintenance Treatment

Cannabis and opioids are substances that affect reproductive health. Opioids suppress testosterone and studies have shown that cannabis may increase testosterone. However, there is minimal research describing the endocrine effects of concurrent cannabis and opioid use. We hypothesize that cannabis use improves opioid-induced testosterone suppression. To test this hypothesis, we used cross-sectional data from a prospective cohort study including 122 men enrolled in methadone maintenance treatment (MMT). We measured serum testosterone with an enzyme-linked immunosorbent assay at study enrolment. Urine drug screens were collected for 15 months and identified 52.5% of participants (n = 64) as cannabis users. The association between cannabis use and testosterone level was examined using regression models with serum testosterone as the dependent variable. In our multivariable regression, methadone dose was associated with lower serum testosterone (β = −0.003, 95% CI-0.005, −0.001, p = 0.003). However, neither cannabis use as a dichotomous variable nor the percentage of cannabis-positive urine drug screens were significantly associated with serum testosterone (β = 0.143, 95% CI −0.110, 0.396, p = 0.266, and β = 0.002, 95% CI > −0.001, 0.005, p = 0.116, respectively). Therefore, it does not appear that cannabis has an association with testosterone levels in men on MMT.