Abstract: This invention relates to compounds which modulate receptors of the 5-HT2 family of receptors, and particularly to compounds which modulate 5-HT2C receptors. Compounds of the invention include agonists and selective agonists for the 5-HT2C receptor Compounds of the invention include selective agonists for the 5-HT2C receptor which exhibit significantly less or no agonist activity on the 5-HT2A receptor and/or the 5-HT2B receptor. Compounds of this invention are those of Formula I and pharmaceutically acceptable salts, esters and solvates (including hydrates) wherein variables are defined in the specification hereof.