Aliskiren is an anti-hypertensive (blood pressure lowering) medication. It works by decreasing substances in the body that narrow blood vessels and raise blood pressure. Valsartan is in a group of drugs called angiotensin II receptor antagonists. Valsartan keeps blood vessels from narrowing, which lowers blood pressure and improves blood flow. The combination of aliskiren and valsartan is used to treat high blood pressure (hypertension). Aliskiren and valsartan may also be used for purposes not listed in this medication guide.