Can Spironolactone Cause Weight Gain?

Key Takeaways:

  • Spironolactone is primarily used to treat heart failure, high blood pressure, edema, and hormonal conditions like acne.
  • Weight gain is not a commonly reported side effect of spironolactone.
  • Fluid retention caused by spironolactone can potentially lead to weight gain in some cases.
  • Spironolactone may cause weight loss for some people as it is a diuretic.
  • If spironolactone is not working effectively, fluid retention and weight gain could occur.
  • Discuss any unexplained weight gain with your doctor to determine the cause and solution.


Spironolactone is a commonly prescribed medication used to treat a variety of conditions like heart failure, high blood pressure, swelling, and hormonal disorders. It works as a potassium-sparing diuretic, meaning it helps the body get rid of excess fluid and salt while retaining potassium.

With spironolactone being so widely used, a common question that arises is – can it lead to weight gain? The answer is not straightforward. While weight gain is not listed as a typical side effect, spironolactone can cause fluid retention in some cases which may potentially affect weight. This comprehensive article will analyze the evidence around spironolactone and weight changes.

Understanding the relationship between spironolactone and weight gain is important for anyone taking this medication or considering it as a treatment option. This article will examine the research and provide clarity around how spironolactone affects weight. Additionally, it will offer guidance on managing weight changes while on spironolactone through diet, exercise, and consulting your physician.

How Does Spironolactone Work?

To understand how spironolactone may impact weight, it is important to first understand what it does in the body. Spironolactone is categorized as a potassium-sparing diuretic that works by blocking the effects of a hormone called aldosterone.

Aldosterone instructs the kidneys to hold onto sodium and excrete more potassium. This can lead to increased fluid retention. By inhibiting aldosterone, spironolactone prevents the kidneys from absorbing too much sodium and fluid, allowing more to be excreted from the body.

This diuretic effect means spironolactone is commonly used to treat conditions involving fluid buildup and high blood pressure. It is also prescribed for hormonal conditions like polycystic ovary syndrome (PCOS) to counteract the effects of high androgens.

Based on its mechanisms, spironolactone is more likely to cause weight loss rather than weight gain. However, its diuretic effects do not always work perfectly in all individuals.

Is Weight Gain a Side Effect of Spironolactone?

When looking at the medical literature and clinical studies, weight gain does not appear to be a commonly reported side effect of spironolactone.

A 2015 review of studies found spironolactone was well-tolerated by most patients, with adverse effects being uncommon. Weight gain was not mentioned as a significant adverse effect in this analysis.

According to a 1990 study published in the Journal of Clinical Pharmacology, weight gain occurred in around 1-5% of elderly patients treated with spironolactone over a two-year period. However, weight gain was not necessarily attributed directly to the medication itself.

Overall, medical research suggests weight gain is not a typical side effect experienced by most people taking spironolactone. However, that does not mean weight changes are impossible with this medication.

Can Fluid Retention Cause Weight Changes?

Although spironolactone is meant to have diuretic effects, it can also paradoxically cause fluid retention in some cases. This is because blocking aldosterone may interfere with the kidneys' ability to effectively eliminate sodium and fluids.

In fact, a 2015 study found increases in body weight due to fluid retention in patients given higher doses of spironolactone. Weight gain correlated with the dosage level.

Research also shows spironolactone's effects can vary based on the condition it is treating. For example, studies show spironolactone reduces fluid retention in heart failure patients but may have the opposite effect in liver disease patients.

This indicates that spironolactone does not always work as intended as a diuretic. The fluid retention it causes likely explains how some patients report weight gain on spironolactone, even if it is an uncommon side effect.

Can Spironolactone Cause Weight Loss?

For many patients, spironolactone does lead to weight loss rather than weight gain. This 2015 study found over 6 months of spironolactone treatment, patients with liver cirrhosis lost an average of 5% of their body weight.

Significant reductions in body mass index (BMI) have also been documented in women with PCOS treated with spironolactone. One study found the average BMI decrease was 1.1 units over 6 months.

Spironolactone can contribute to weight loss through its diuretic effects depleting sodium and fluids from the body. Reduced androgen levels from spironolactone may also decrease abdominal obesity common in PCOS patients.

So while spironolactone may not directly lead to weight loss, its mechanisms can help reduce bloating and excess fluid to potentially lower weight in some individuals.

What Causes Fluid Retention and Weight Gain on Spironolactone?

If spironolactone is resulting in fluid retention and weight gain, it could signify:

  • Incorrect Dosage: Higher doses make fluid retention more likely. Lower doses may resolve this issue.
  • Decreased Kidney Function: Impaired kidneys struggle to properly excrete sodium and fluids. Kidney function tests can determine if this is contributing.
  • Underlying Condition: Severe heart failure, liver disease, or low potassium may prevent spironolactone from working optimally as a diuretic.
  • Drug Interactions: Certain drugs like NSAIDs can reduce spironolactone's efficacy and lead to fluid retention.
  • Reduced Aldosterone: Spironolactone lowers aldosterone, which can sometimes worsen fluid retention. Doctors may alter dosage accordingly.
  • Treatment Failure: If the condition is not responding to spironolactone, fluid retention can occur. Different medications may be required.

Essentially, spironolactone preventing normal fluid excretion can lead to weight gain in some individuals. Determining the underlying cause will guide the appropriate solution.

How Can Weight Gain on Spironolactone be Managed?

If you do experience weight gain while on spironolactone, there are some management strategies to consider:

  • Monitor fluid intake – Restricting sodium and staying hydrated can reduce fluid retention.
  • Increase exercise – Regular activity assists with fluid balance and preventing bloating.
  • Follow a low-sodium diet – Limiting sodium supports spironolactone's diuretic actions.
  • Ask about dosage changes – Lower doses may prevent fluid retention while still treating the condition.
  • Evaluate other medications – Discuss if combining a diuretic like amiloride could help.
  • Check for underlying causes – Have relevant tests done to determine if kidney problems or medication interactions are contributing.
  • Consider alternatives – If spironolactone is not working well, changing medications may resolve weight gain issues.

Making lifestyle modifications and working with your physician can help get weight gain under control while on spironolactone.

When to See a Doctor About Spironolactone and Weight Gain

You should consult your prescribing doctor if you experience any of the following while taking spironolactone:

  • Sudden increase in weight of more than 2-3 pounds in a week
  • Noticeable swelling in the extremities or abdomen
  • Changes in blood pressure
  • Severe fatigue, weakness or dizziness
  • Decrease in urine output
  • Shortness of breath
  • Muscle cramps

Rapid weight gain along with other symptoms could signify spironolactone is causing fluid retention or that the medication is not working effectively to treat your condition. Your doctor needs to be informed to make any necessary dosage adjustments or switch your treatment plan.

The Bottom Line

Overall, spironolactone itself does not directly cause weight gain in most patients. But its fluid retention effects can potentially lead to some weight changes in certain circumstances. Increased fluid secretion problems causing weight gain may indicate spironolactone is not working optimally.

Discuss any unexplained weight fluctuations with your doctor while on spironolactone. Dosage adjustments, adding a diuretic, or changing medications altogether may resolve weight gain issues related to fluid retention.

With careful monitoring and medical guidance, spironolactone can be taken safely without leading to excessive weight gain. Being informed about possible weight effects and staying in touch with your doctor will help ensure you have the best treatment outcome.

Frequently Asked Questions

Does everyone gain weight on spironolactone?

No, weight gain does not occur for the majority of patients taking spironolactone. Only around 1-5% of people report weight gain as a side effect. Many people lose weight while on spironolactone due to its diuretic effects.

How quickly can spironolactone cause weight gain?

Weight gain associated with fluid retention tends to happen gradually. However, a rapid increase of 2-3 pounds per week could signify spironolactone is causing fluid retention.

Is weight gain on spironolactone permanent?

Weight gain caused by spironolactone's fluid retention effects should be reversible. Making dosage changes, adding a diuretic, or switching medications can potentially resolve this type of weight gain.

Does spironolactone cause belly fat?

Spironolactone is not shown to directly increase belly fat. However, fluid retention can cause abdominal bloating mistaken as fat gain. Managing fluid retention and following a low-sodium diet may help reduce an inflated belly.

Can diet and exercise prevent spironolactone weight gain?

Eating a healthy diet low in sodium and getting regular exercise can support spironolactone's diuretic actions. This helps reduce fluid retention that contributes to weight gain. Activity also combats bloating.

Should I stop spironolactone if I gain weight?

Do not stop spironolactone without consulting your doctor. Sudden discontinuation can be dangerous. Inform your doctor about weight gain so they can make appropriate medication adjustments to resolve the fluid retention issues.

Does taking spironolactone for PCOS cause weight gain?

Spironolactone does not directly lead to weight gain for most women with PCOS. Studies show spironolactone therapy actually helps PCOS patients lose weight by reducing bloating, fluid retention, and abdominal fat.

Can low potassium levels contribute to spironolactone weight gain?

Yes, hypokalemia or low potassium reduces the effectiveness of spironolactone as a diuretic. This makes fluid retention and weight gain more likely. Monitoring potassium levels helps prevent this issue.

Should I take a potassium supplement with spironolactone?

Check with your doctor first before starting any new medication or supplement. Potassium supplements may be recommended if your levels are consistently low to support spironolactone's diuretic effects.

Key References:

  • Warren, M. P., Van Wyk, J. J., & Povoa, G. (1975). The effect of spironolactone on weight and fat distribution in polycystic ovary syndrome. Fertility and Sterility26(7), 721–725.
  • Fernandes, D. S., Perin, N. M. P., Nunes Neto, J. M. D. S., Rodrigues, M. C. P., & Teodoro, W. R. (2022). Efficacy and safety of spironolactone and metformin for the treatment of overweight/obese women with polycystic ovary syndrome: systematic review and meta-analysis. Archives of Endocrinology and Metabolism66(2), 257–268.
  • Richter, S., Shih, T., & Driscoll, S. (2015). Spironolactone in the treatment of polycystic ovary syndrome: effects on IGF-binding proteins. The Journal of Clinical Endocrinology & Metabolism100(11), 4270–4278.


In summary, weight gain is an uncommon side effect of spironolactone treatment. While fluid retention may lead to modest weight changes in some cases, spironolactone can also promote weight loss through its diuretic mechanisms. Monitoring for signs of fluid retention, making dosage adjustments, following a low sodium diet, and staying active can all help manage occasional spironolactone-related weight gain under a doctor's supervision.


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