Marijuana, ∆9-THC, and other cannabinoids acutely alter hypothalamic-pituitary-gonadal (HPG) integrity and affect reproductive function by acting at the hypo- thalamus either directly through GnRH or indirectly through other modulators (Figure 1). These effects are likely mediated by central cannabinoid (CB1) receptors in the hypothalamus.2 CB1 receptors have also been found in the testes3 and the ovaries4 of experimen- tal animals, suggesting a possible direct effect of cannabinoids on the gonads. In addition, marijuana condensate and ∆9-THC inhibit binding of dihydrotes- tosterone (DHT) to the androgen receptor,5 and noncannabinoid components of marijuana extract have been shown to bind to the estrogen receptor.