The present invention provides a compound of the formula:or a pharmaceutically acceptable salt thereof; pharmaceutical compositions comprising aa compound of Formula (I) in combination with a suitable carrier, diluent, or excipient; and methods for treating physiological disorders, particularly reduced bones mass, osteoporosis, osteopenia, or reduced muscle mass or strength, comprising administering a compound of Formula (I), or a pharmaceutically acceptable salt thereof.本發明提供下式化合物:或其醫藥學上可接受之鹽;包含式(I)化合物與適合載劑、稀釋劑或賦形劑之組合之醫藥組合物;及用於治療生理病症,尤其為骨質量降低、骨質疏鬆症、骨質減少或肌肉質量或強度降低之方法,其包含投與式(I)化合物或其醫藥學上可接受之鹽。