Active Ingredient

Losartan

Losartan is a medication commonly used to help manage high blood pressure. By helping to relax blood vessels, it makes it easier for blood to flow.

This medication is often prescribed to reduce the risk of strokes in patients with certain heart conditions and to protect the kidneys in people with diabetes.

Written By Douglas C. Goldberg, MD

Reviewed By Philip Schein, MD

Last Updated 28 Nov 2025

Available Losartan Brands

Cozaar

Strengths 25mg, 50mg, 100 mg

Losartan Uses

Losartan is used to manage several health conditions related to the heart and blood vessels.

High blood pressure (hypertension)
Reducing the risk of stroke in patients with heart disease
Protecting kidney function in people with type 2 diabetes
Heart failure management
Improving survival after a heart attack

How Losartan Works

Losartan works by blocking the action of a natural substance called angiotensin II, which normally tightens blood vessels. By preventing this action, Losartan helps to relax and widen blood vessels.

This relaxation of blood vessels leads to a decrease in blood pressure, reducing the workload on the heart.

As a result, it helps to lower the risk of strokes and kidney damage in people with diabetes.

Common side effects of Losartan

While many people using Losartan do not experience significant side effects, some may occur. Most side effects are mild and temporary.

Dizziness
Fatigue
Headache
Nasal congestion
Back pain
Stomach upset
Diarrhea
Cough

If you experience serious or persistent symptoms, contact your healthcare provider.

Monitor your blood pressure regularly to ensure the medication is working effectively.
Avoid excessive consumption of alcohol while taking Losartan.
Inform your doctor of any other medications or supplements you are taking to avoid interactions.
Do not use Losartan if you experience significant kidney or liver issues without consulting a healthcare provider.
Be cautious when standing up quickly, as Losartan can cause dizziness.

Always consult your doctor for personalized medical advice and before making any changes to your medication regimen.

Frequently Asked Questions

How long does it take for Losartan to work?

Losartan may start to lower your blood pressure within a few hours, but it may take a few weeks to see the full effect.

Can I stop taking Losartan if my blood pressure is normal?

No, you should not stop taking Losartan without consulting your healthcare provider, even if your blood pressure is normal.

Is it safe to take Losartan during pregnancy?

Losartan is not recommended during pregnancy. Consult your doctor for alternative treatments if you are pregnant or planning to become pregnant.

Can Losartan be taken with other blood pressure medications?

Sometimes Losartan is used with other medications to manage blood pressure. Always follow your doctor’s advice on medication combinations.

What should I do if I miss a dose of Losartan?

If you miss a dose, take it as soon as you remember. If it’s almost time for your next dose, skip the missed dose and continue with your regular schedule.