A full agonist of the serotonin 5-HT7 receptor (Ki = 0.22 nM) that displays 200- and greater than 1,000-fold selectivity over 5-HT1A (Ki = 52.7 nM) and 5-HT2A (Ki = 326 nM) receptors, respectively; induces relaxation of substance P-induced guinea pig ileum contraction with an EC50 value of 2.56 μM.