Valsartan is one of a group of eight presently available nonpeptide orally active angiotensin type 1 receptor drugs collectively called “sartans” that cause vasoconstriction and retention of sodium and fluid. They act by binding to the main effector of the renal-angiotensin system as AII receptor antagonists and are thus used in the treatment of essential hypertension and heart failure. Valsartan is available by prescription as Diovan®, and it has a pregnancy category ranging from C to D. The package label refers to studies conducted orally, the route of administration for valsartan in the human, in mice, rats, and rabbits. In the human, valsartan has been associated with a few cases of fetopathy late in pregnancy. Valsartan is a large compound with a high polar surface area. It is slightly hydrophilic and is capable of participating as both a hydrogen bond acceptor and as a hydrogen bond donor.