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 work by relaxing blood vessels, making it easier for the heart to pump blood. This helps lower blood pressure and reduces the risk of heart-related complications. In addition to hypertension, losartan may also be prescribed to protect the kidneys in patients with diabetes. It is usually taken as a tablet once daily and can be used alone or in combination with other medications. Common side effects may include dizziness, fatigue, and headaches.