Valsartan is in the class of medications referred to angiotensin II receptor blockers (ARBs) and is used to treat high blood pressure and heart failure. It works by blocking the effects of angiotensin II, a hormone that causes blood vessels to constrict. By preventing this constriction, valsartan helps relax and widen blood vessels, which lowers blood pressure and improves blood flow. This medication is also used to improve survival after a heart attack and reduce the risk of strokes and kidney damage in people with hypertension or diabetes.