Does Losartan Cause Weight Gain? What You Need to Know

October 9, 2025 •

4 min read

While many medications can affect body weight, clinical studies have not identified weight gain as a common side effect of losartan. For individuals on this medication, the question, 'Does losartan cause weight gain?' is a frequent query, especially since some other blood pressure drugs are known to cause weight fluctuations.

Quick Summary

Losartan, a blood pressure medication, does not typically cause weight gain. Any weight increase is usually due to fluid retention (edema), a less common side effect, rather than true fat accumulation.

Key Points

Weight-Neutral Profile: Losartan is not known to cause weight gain and is generally considered a weight-neutral blood pressure medication.
Fluid Retention is Not Fat Gain: Any weight increase from losartan is typically due to fluid retention (edema), a less common side effect, not an accumulation of body fat.
Better Profile Than Other Meds: Losartan is less likely to cause weight gain than older beta-blockers and is often a preferred option for patients concerned about weight.
Monitor for Edema: Patients experiencing unexplained weight changes should check for swelling in their ankles, feet, or legs and contact their doctor.
Consult a Doctor for Changes: If you notice significant or rapid weight gain, talk to your healthcare provider to identify the cause and determine the best course of action.
Animal Studies Suggest Possible Benefit: Some animal studies have shown that losartan might reduce weight gain in the context of a high-fat diet, though human evidence for this is less clear.

What Is Losartan and How Does It Work?

Losartan is a prescription medication belonging to a class of drugs called angiotensin II receptor blockers (ARBs). It is primarily used to treat high blood pressure (hypertension), but is also prescribed for heart failure and to protect the kidneys in people with type 2 diabetes and hypertension. Losartan works by blocking the effects of angiotensin II, a natural substance in the body that constricts blood vessels. By blocking this substance, losartan allows blood vessels to relax and widen, which lowers blood pressure and improves blood flow throughout the body.

Does Losartan Cause Weight Gain? The Clinical Evidence

The good news for those concerned about their weight is that losartan is not typically associated with weight gain. Weight changes were not reported as a side effect in the clinical trials conducted for the drug. This makes it a weight-neutral option compared to some other antihypertensive medications. In fact, some preliminary studies on animals and some anecdotal reports suggest it may even have beneficial effects on metabolism and fat accumulation, particularly in the context of high-fat diets, though this has not been conclusively demonstrated in human trials.

Edema: A Key Distinction from Fat Gain

While losartan does not typically cause fat gain, some people may experience an increase on the scale due to a less common side effect called edema, or fluid retention. Edema can cause noticeable swelling or puffiness in the ankles, feet, or legs. This is not the same as gaining body fat. Fluid retention can happen more quickly, sometimes even overnight, whereas fat gain occurs over weeks or months from consuming more calories than you burn. If you notice sudden or significant weight changes (e.g., 2 to 5 pounds in a week) accompanied by swelling, it is crucial to contact your healthcare provider, as this could be a sign of fluid buildup.

Losartan vs. Other Blood Pressure Medications

The impact on weight is a common point of comparison among different blood pressure medications. Losartan's neutral effect on weight is a distinct advantage over some other classes of antihypertensives.

Beta-Blockers

Some older beta-blockers, such as atenolol and metoprolol, are well-known for causing weight gain. It is believed this happens because they can slow metabolism and reduce energy levels, making it more difficult to burn calories. Newer beta-blockers, like carvedilol, are less likely to have this effect.

ACE Inhibitors

Angiotensin-converting enzyme (ACE) inhibitors, such as lisinopril, generally have a neutral to slightly positive effect on weight, similar to losartan. Like losartan, they are often a preferred choice when weight is a concern.

Comparison Table of Blood Pressure Medications and Weight Impact


Medication Class	Common Examples	Typical Impact on Weight	Notes on Weight Change
ARBs (e.g., Losartan)	Losartan, Valsartan	Generally Weight-Neutral	Edema (fluid retention) is a possible, though uncommon, cause of weight increase.
Older Beta-Blockers	Atenolol, Metoprolol	Potential for Weight Gain	Can slow metabolism and decrease energy expenditure.
ACE Inhibitors	Lisinopril, Enalapril	Generally Weight-Neutral	Small weight loss reported in some studies, but often considered weight-neutral.
Calcium Channel Blockers	Amlodipine, Nifedipine	Potential for Fluid Retention	Can cause peripheral edema, leading to a temporary weight increase from fluid, not fat.

What to Do If You Notice Weight Changes on Losartan

If you are taking losartan and experience unexplained weight changes, the first step is to consult your healthcare provider. They can help determine the cause and rule out any serious complications. In the meantime, you can take some proactive steps:

Monitor your weight consistently: Weigh yourself at the same time each morning using the same scale and keep a daily record. This helps you track changes and distinguish between small fluctuations and a significant trend.
Check for swelling: Regularly check your feet, ankles, and hands for any signs of puffiness or swelling.
Limit salt intake: Reducing sodium in your diet is one of the most effective ways to combat fluid retention.
Stay active: Regular physical activity, such as walking, can help improve circulation and reduce swelling.
Communicate with your doctor: Be prepared to discuss any symptoms or patterns you notice. Your doctor may adjust your dose or, if necessary, prescribe a diuretic to help manage the fluid buildup.

Conclusion: Is Losartan a Weight-Neutral Option?

Losartan is widely considered a weight-neutral medication, meaning it does not typically cause weight gain. While a less common side effect, fluid retention (edema) can cause an increase on the scale for some individuals, which is a temporary fluid buildup rather than true fat. Compared to older beta-blockers, losartan poses a much lower risk for medication-induced weight gain. Patients who experience unexpected weight changes while on losartan should track their symptoms and consult a healthcare professional to identify the cause and ensure their treatment remains safe and effective.

Potential Side Effects of Losartan

Beyond the question of weight, losartan, like any medication, can cause other side effects. Common side effects include:

Dizziness or lightheadedness, especially when standing up quickly
Fatigue or tiredness
Headaches
Muscle cramps or back pain
Mild upper respiratory symptoms, such as a cough or stuffy nose

Serious, though rare, side effects can include severe allergic reactions (angioedema) or high potassium levels, which require immediate medical attention.

Frequently Asked Questions

No, losartan is not known to cause weight gain. In clinical trials, weight gain was not reported as a side effect.

Yes, but any weight gain is not typically from an increase in body fat. A less common side effect is fluid retention (edema), which can cause temporary weight gain.

Fluid gain, or edema, can happen quickly and cause swelling, especially in your ankles, feet, or legs. Fat gain typically occurs gradually over time due to calorie intake.

Yes, older beta-blockers like metoprolol and atenolol are more consistently associated with weight gain than losartan, making losartan a more weight-neutral option.

If you notice sudden or unexplained weight changes, especially with swelling, you should contact your healthcare provider. Do not stop taking your medication on your own.

While not a common effect, some healthcare providers have speculated that losartan could potentially aid weight loss in some patients, due to a rare side effect of decreased appetite. However, you should not expect this effect.

Your doctor may adjust your dose, recommend dietary changes such as reducing salt, or prescribe a mild diuretic (water pill) to help your body eliminate the excess fluid.