Simvastatin acid is the active β-hydroxy acid metabolite of simvastatin formed in vivo. Simvastatin acid is a potent inhibitor of 3-hydroxy-3-methylglutarylcoenzyme A (HMG-CoA) reductase, an essential enzyme involved in the in vivo synthesis of cholesterol. Simvastatin acid stimulates bone formation by increasing expression of BMP-2 (bone morphogenic protein-2) in osteoblasts.
