PCO371 (2,4-Imidazolidinedione, 1-(3,5-dimethyl-4-(2-((4-oxo-2-(4-(trifluoromethoxy)phenyl)-1,3,8-triazaspiro(4.5)dec-1-en-8-yl)sulfonyl)ethyl)phenyl)-5,5-dimethyl-) is an orally active full agonist of parathyroid hormone receptor 1. It has no effect on PTH type 2 receptor.