Losartan is a medication primarily used to treat high blood pressure, also known as hypertension. It belongs to a class of drugs called angiotensin II receptor blockers (ARBs), which help relax blood vessels, making it easier for the heart to pump blood. This can reduce the risk of stroke and heart attack. In addition to managing hypertension, Losartan is sometimes prescribed to protect the kidneys in patients with diabetes. It is typically taken once daily and can be used alone or in combination with other medications. Common side effects may include dizziness, fatigue, and headaches.