CB1 antagonists are provided. Such compounds may be used to modulate CB1 activity in vivo or in vitro, and are particularly useful in the treatment of conditions responsive to CB1 receptor modulation in humans, domesticated companion animals and livestock animals, including appetite disorders, obesity and addictive disorders. Pharmaceutical compositions and methods for using them to treat such disorders are provided, as are methods for using ligands for receptor localization studies and various in vitro assays.