The Wellness Collective

What to Know About Losartan

Mariah Powers
February 13, 2026

Reviewed by Ashley Robinson, PharmD, Pharmacy Manager for TelyRx

Losartan (brand name Cozaar) is an oral prescription medication used to treat high blood pressure (hypertension). It belongs to a class of drugs known as angiotensin II receptor blockers (ARBs).

Beyond managing blood pressure, losartan is used to reduce the risk of stroke in people who have both high blood pressure and a heart condition known as left ventricular hypertrophy. Losartan is also prescribed to protect kidney function in people with type 2 diabetes who have diabetic nephropathy, a form of kidney disease.

how does Losartan work?

As an angiotensin II receptor blocker, losartan works by blocking a hormone called angiotensin II. Angiotensin II binds to receptors in the blood vessels, causing them to narrow and triggering the release of another hormone, aldosterone, which causes the body to retain salt and water.

By blocking these receptors, losartan has three main effects:

It allows the blood vessels to relax and widen, helping blood to flow more easily and lowering blood pressure.
It decreases the workload on the heart.
It prevents the kidneys from reabsorbing too much sodium and water into the body.

drug facts

Common Brands	Cozaar
Drug Class	Angiotensin II receptor blocker (ARB)
Generic Status	Generic version of Cozaar
Availability	Prescription Only

dosing

Note: Dosing information below is educational only. Your prescribing physician will determine your specific dose based on your individual health needs.

Losartan comes in three dosage strengths: 25 mg, 50 mg, and 100 mg.

The recommended starting dose for adults is usually 25 mg or 50 mg taken by mouth once daily. Depending on how blood pressure responds, a provider may increase the dose to a maximum of 100 mg once daily.

Always follow your healthcare provider’s instructions for exact dosing.

FDA-approved uses

Losartan is FDA-approved to:

Lower high blood pressure (hypertension)
Reduce the risk of stroke in people with high blood pressure and left ventricular hypertrophy (Note: Studies suggest this benefit may not apply to Black people with these conditions.)
Slow the progression of kidney damage in people with type 2 diabetes and nephropathy, a type of kidney disease

common off-label uses

You may see losartan prescribed for uses that are not “FDA-approved.” This is a very common and legal practice called “off-label” prescribing, where a doctor uses their clinical judgment to prescribe a drug for a different (but well-researched) purpose.

While losartan is FDA-approved for blood pressure and angina, healthcare providers may prescribe it for other heart conditions, such as acute coronary syndrome and stable coronary artery disease.

side effects

Like all medications, losartan can cause side effects. Common side effects may improve as your body adjusts to the medication, but others may be serious and require medical attention.

Common Side Effects

Dizziness
Common cold
Nasal congestion
Back pain

Serious Side Effects

Serious side effects are rare, but it’s important to know what to look for if they do occur. Stop using losartan and call your doctor immediately if you experience:

Low Blood Pressure (Hypotension) – This can cause severe dizziness, fainting, lightheadedness, or confusion, especially when standing up or dehydrated.
Kidney Damage – Signs include urinating less than usual; swelling in the feet, ankles, or legs; unexplained weight gain; weakness; confusion; nausea; and chest pain or pressure.
High Potassium Levels (Hyperkalemia) – Symptoms include muscle weakness, unusual tiredness, slow or irregular heartbeat, nausea, vomiting, or difficulty breathing.
Severe Allergic Reactions – Swelling of the face, lips, tongue, or throat; difficulty breathing or swallowing; severe rash or itching; fever.
Pregnancy – Losartan can cause injury or death to an unborn fetus. It should not be used during pregnancy.

Call your doctor immediately if you experience any concerning or prolonged symptoms.

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Losartan

Losartan is a medication used to help lower blood pressure.

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pharmacist tips

Be Consistent – Take losartan at the same time each day.
Avoid NSAIDs – Do not take nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (Advil, Motrin) or naproxen (Aleve) for headache or pain relief, without checking with your doctor, as combining them with losartan can increase the risk of kidney damage.
Watch Potassium Intake – Losartan can increase potassium levels in your body. Avoid using salt substitutes that contain potassium or eating thigh-potassium foods like bananas.
Follow a Low-Salt Diet – Your healthcare provider may recommend a low-sodium diet when taking losartan to help lower blood pressure.
Avoid or Limit Alcohol – While alcohol is not known to directly interact with losartan, it can lower blood pressure and increase side effects like dizziness.
Missed Dose – If you miss a dose, take it as soon as you remember. If it is almost time for the next dose, skip the missed one and take your next dose as usual. Do not take two doses at once.
Pregnancy Warning – If you are pregnant or plan to become pregnant, tell your doctor immediately and stop taking losartan.
Monitor Blood Pressure – Keep checking your blood pressure at home and maintain a log to help your doctor determine if the medication is working effectively for you.

drug interactions

Losartan can interact with other medications, potentially altering their effectiveness or increasing side effects. For example:

Lithium – Losartan may interact with lithium, a medication used for depression, potentially increasing lithium levels in the body.
Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) – Pain relievers like ibuprofen, naproxen, and celecoxib can increase the risk of kidney problems when taken with losartan.
Potassium Supplements – Taking potassium pills or using potassium-containing salt substitutes can lead to dangerously high potassium levels (hyperkalemia).
ACE Inhibitors – Taking losartan with drugs like lisinopril or enalapril can increase the risk of low blood pressure and kidney issues.
Aliskiren – This blood pressure medicine should not be used with losartan, especially in patients with diabetes.
Diuretics – “Water pills” can increase the risk of low blood pressure and electrolyte imbalances when taken with losartan.

Always give your doctor and pharmacist a complete list of all your medications, vitamins, and supplements to check for potential interactions.

FAQs

Why is losartan preferred over lisinopril for some patients?

As an ACE inhibitor, lisinopril can cause a dry, hacking cough as a side effect. Because losartan is an ARB, a different kind of medication, it works similarly to treat high blood pressure but is less likely to cause this cough, making it a preferred alternative for some people.

Can I eat bananas while taking losartan?

It’s best to be cautious. Bananas are high in potassium, and losartan can raise potassium levels in your body. While an occasional banana may be fine, eating bananas regularly or eating them with other potassium sources could lead to a condition called hyperkalemia (dangerously high levels of potassium). Ask your doctor what they recommend based on your level of risk.

Does losartan cause a dry cough?

It is unlikely. While a cough can happen, losartan is specifically noted for having fewer side effects like cough compared to ACE inhibitors like lisinopril.

Is it better to take losartan in the morning or at night?

The best time to take losartan is whatever time works best for you, as long as you are consistent. Some providers may suggest a specific time or even splitting the dose to twice a day for certain patients, so follow your healthcare provider’s instructions.

How long does it take for losartan to work?

Losartan starts working within several hours, but it typically takes about a week to see a drop in blood pressure. It may take several weeks to see the full benefits of the medication.

Can losartan cause sudden weight gain or swelling?

Sudden weight gain or swelling in the feet and ankles can be a sign of kidney damage or heart failure, which are serious conditions. If you experience unexplained weight gain on losartan, contact your provider.

Can I drink alcohol while taking losartan?

Alcohol is not known to directly interact with losartan, but drinking can lower blood pressure and increase the risk of side effects like dizziness and fainting. Your healthcare provider may recommend limiting or avoiding alcohol while taking losartan.

Does losartan cause hair loss?

Hair loss is not listed as a common side effect for losartan. If you experience hair loss on losartan, contact your doctor to understand what may be causing it.

Can losartan cause erectile dysfunction?

Erectile dysfunction (inability to have or keep an erection) is not listed as a common side effect of the medication. There are several possible causes for erectile dysfunction. If you experience ED on losartan, make an appointment with your healthcare provider.

Does losartan cause constipation?

Constipation, or difficulty having a bowel movement, has been reported as a less common side effect of losartan.

Does losartan make you sleepy?

It can. Tiredness and sleepiness are common side effects of losartan.

Is losartan a beta blocker?

No, losartan is not a beta blocker. It is an angiotensin II receptor blocker (ARB).

compare medications

Compared: Losartan, Valsartan, Lisinopril, Ramipril, Losartan-Hydrochlorothiazide, or Amlodipine?

There are several medications that your doctor can prescribe in place of losartan. Here are a few possible alternatives below.

Valsartan – Another angiotensin II receptor blockers (ARB) like losartan that is used to treat high blood pressure, heart failure, and left-sided heart failure after a heart attack.
Lisinopril – An ACE inhibitor that is used to treat high blood pressure or heart failure, but may cause cough as a side effect.
Ramipril – Another ACE inhibitor that is used to treat high blood pressure and heart failure, and may cause cough as a side effect.
Losartan-Hydrochlorothiazide – A combination pill that contains both losartan and a diuretic (water pill) called hydrochlorothiazide, which may be used when losartan alone is not enough to lower blood pressure.
Amlodipine – A calcium channel blocker that is used to treat high blood pressure and chest pain (angina).

Disclaimer

Important: Information on this page is for educational purposes only. Prescribing decisions are made by independent, licensed providers. TelyRx operates technology-enabled pharmacies and a telehealth platform that connects patients with board-certified licensed providers. Prescriptions, when provider-approved and issued, are filled and shipped by TelyRx-affiliated pharmacies. We do not employ physicians or make prescribing decisions. Learn more about our editorial standards here.

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