What Is Losartan? Uses, Dosage, and What You Need to Know in 2026

Losartan — sold under the brand name Cozaar — is one of the most prescribed medications in the United States. In 2023, it ranked as the 8th most commonly prescribed drug in the country, with more than 56 million prescriptions filled. If you or a family member has high blood pressure, diabetic kidney disease, or has been told they're at risk for stroke, there's a good chance losartan has come up in a conversation with your doctor.

This guide covers everything patients and caregivers need to know about losartan in 2026 — including what it treats, how to take it, what it costs, and how to get your prescription filled.

What Is Losartan?

Losartan is an angiotensin II receptor blocker (ARB) — a class of medications that works by blocking a hormone called angiotensin II, which naturally tightens blood vessels. By blocking this hormone, losartan allows blood vessels to relax and widen, which lowers blood pressure and reduces the workload on the heart and kidneys.

It was first approved by the FDA in 1995 and is on the World Health Organization's List of Essential Medicines. Generic losartan has been available since the mid-2000s and is now extremely affordable.

What Is Losartan Used For?

The FDA has approved losartan for three main indications:

1. 1. High blood pressure (hypertension) — in adults and children 6 years and older. Losartan is considered a first-line medication for hypertension, especially in patients with diabetes, kidney disease, or heart conditions. It may be used alone or combined with other blood pressure medications.
2. 2. Diabetic nephropathy — kidney disease caused by type 2 diabetes in patients with high blood pressure. Losartan slows the progression of kidney damage, reducing protein in the urine (proteinuria) and protecting kidney function over time.
3. 3. Stroke risk reduction — in patients with high blood pressure who also have left ventricular hypertrophy (enlarged heart walls). The landmark LIFE trial showed losartan significantly reduced stroke risk in this population. Note: this benefit may not apply to African American patients with LVH.

Losartan Dosage: What Does a Typical Prescription Look Like?

Losartan is available as oral tablets in three strengths: 25 mg, 50 mg, and 100 mg. There is also a liquid suspension (10 mg/mL) for children or adults who can't swallow tablets.

• For hypertension: The usual starting dose is 50 mg once daily. Your doctor may increase to 100 mg once daily if needed. Some patients start at 25 mg if they're on a diuretic or may be volume-depleted.
• For diabetic nephropathy: Starting dose of 50 mg once daily, which may be increased to 100 mg once daily based on blood pressure response.
• For stroke prevention (LVH): Starting dose of 50 mg once daily, increased to 100 mg as needed. Often combined with hydrochlorothiazide.

Losartan is taken once daily, with or without food. It may take up to 6 weeks to see the full blood pressure-lowering effect. Don't stop taking it without talking to your doctor first — your blood pressure can rebound rapidly.

What Is Losartan/HCTZ (Hyzaar)?

Losartan is also available as a combination pill with hydrochlorothiazide (a diuretic/water pill), sold as Hyzaar or as generic losartan/HCTZ. The combination can lower blood pressure more effectively than either drug alone. In 2023, this combination was the 65th most prescribed medication in the US, with over 9 million prescriptions.

How Much Does Losartan Cost?

Generic losartan is one of the most affordable prescription medications available:

• With insurance: Losartan is typically a Tier 1 drug (lowest copay tier), with a typical copay of $0–$15 per fill
• With GoodRx or SingleCare: As low as $4–$8 for a 30-day supply
• Retail cash price: ~$55 for 30 tablets of 50 mg (without any discount)

Key Things to Know Before Taking Losartan

• Pregnancy warning: Losartan has a boxed warning for fetal harm. Do not take it if you are pregnant or planning to become pregnant.
• No dry cough: Unlike ACE inhibitors (lisinopril, enalapril), losartan doesn't cause the persistent cough that affects 5-20% of ACE inhibitor users.
• Potassium monitoring: Losartan can raise blood potassium levels. Avoid excessive potassium intake and tell your doctor about all other medications.
• Dehydration risk: If you're vomiting, have diarrhea, or are sweating heavily, call your doctor. Dehydration while on losartan can cause dangerous low blood pressure or kidney problems.

For a deeper look at how losartan works inside your body: How Does Losartan Work? Mechanism of Action Explained

Side effects detail: Losartan Side Effects: What to Expect and When to Call Your Doctor.