Highly potent 5-HT1B receptor agonist (Ki values are 28, 150 and 1490 nM at 5-HT1B, 5-HT1A and 5-HT2 receptors respectively). Decreases central serotonin synthesis and attenuates aggressive behavior in vivo. Also acts as an antagonist at 5-HT3 receptors (Ki = 29.5 nM) and is brain penetrant.