Does spironolactone cause weight gain?

Thanks to spironolactone’s many potential uses, prescriptions for this drug are quite common.  And if you’re like most of us, you’ll want to know the side effects before using any medication. When researching sprionolactone’s side effects, one question that may pop up into your head is, “Does spironolactone cause weight gain?”

The short answer: No clinical evidence suggests spironolactone causes weight gain. In fact, some studies suggest this medication may cause weight loss. But like most things in life, the relationship between spironolactone and the number on the scale is a bit more nuanced than the CliffsNotes version. 

Keep reading to learn more about spironolactone and weight gain.

Spironolactone is a prescription medication that’s approved by the US Food and Drug Administration (FDA) to treat a myriad of medical conditions, including:

• Hypertension (high blood pressure)

• Heart failure

• Low potassium levels (in some circumstances) 

• Edema (swelling caused by excess fluid trapped in tissues) associated with certain medical conditions

It’s also commonly prescribed off-label as a treatment for: 

• Polycystic ovary syndrome (PCOS)

• Hirsutism (excess hair growth on the face, chest, and back)

• Acne

• Female pattern hair loss. In other words, spironolactone can be considered a veritable Swiss Army knife of medications. 

Available as both a generic and brand-name Aldactone, spironolactone is a diuretic medication that belongs to a drug class known as aldosterone receptor antagonists. It is commonly referred to as a “water pill” or potassium-sparing diuretic. Spironolactone helps your body eliminate excess water and sodium without decreasing potassium levels. 

It does this by blocking the activity of aldosterone, a hormone made by the adrenal glands (which are located on top of the kidneys). Aldosterone production occurs naturally and helps the body retain the right amount of sodium and water. Problems can arise when there’s too much aldosterone—and, thus, too much sodium and fluid in the body.  

Spironolactone also blocks the effects of androgens, which are male sex hormones that can contribute to female pattern hair loss as well as hormonal acne. That’s why it’s often prescribed off-label in patients experiencing these symptoms. 

Because spironolactone has effects on hormones, it can also cause side effects such as gynecomastia (increased breast tissue), even in individuals assigned male at birth (typically men). This effect is more likely at higher doses of the medication, and some people may be more likely to develop it than others. The good news is that it is often reversible after stopping the medication or reducing the dose, so be sure to talk to your healthcare provider if you are experiencing this effect (and any other side effects, for that matter).

 Ultimately, spironolactone is a prescription medication. Meaning, a licensed healthcare provider must evaluate your symptoms, consider any potential drug interactions, and assess your medical history before writing an Rx for the drug, which, BTW, usually comes as tablets in 25 mg, 50 mg, and 100 mg strengths. 

It’s unlikely, though there are anecdotal reports of weight gain on spironolactone. 

Weight gain is not listed on the prescribing information for spironolactone. Still, some people uphold that spironolactone has caused them to put on extra pounds. And as mentioned above, the medication has hormonal effects that can include increased breast tissue. So, it’s possible those who experience weight gain on spironolactone had more of that effect. 

That said, weight gain on spironolactone is more likely the direct cause of another issue, such as the conditions that it treats, not the medication itself. PCOS, for example, can contribute to a hormonal imbalance in the body. Patients with the syndrome often have excess androgens, which can promote fat storage and, in turn, weight gain. PCOS can also cause insulin resistance, leading to changes in appetite and, indirectly, weight. 

Heart failure, another condition for which spironolactone may be used, can also be to blame for weight gain on the drug. People with heart failure can sometimes put on excess fluid weight. Spironolactone usually helps with that, so if you are seeing increased fluid retention or water weight after using spironolactone, it’s unlikely to be due to the medication itself.

Moral of the story: Spironolactone itself does not cause weight gain. If you notice weight gain, it’s possible the increase in pounds is the result of your chronic health conditions that need to be addressed rather than directly due to the effects of spironolactone.

But what about weight loss on spironolactone?

The way spironolactone works is by flushing out extra fluids (water and sodium specifically) from the body. In theory, this means you could lose (water) weight fast while on the drug. 

Research does suggest spironolactone may cause mild weight loss in patients with heart failure, in particular. The jury is still out regarding whether spironolactone contributes to weight loss in PCOS, and data show mixed results. 

So before declaring spironolactone the next wonder drug for weight loss, it’s important to note that when weight reductions are found in studies, they are usually minor and largely the result of losing water weight. Water weight naturally fluctuates, and to experience long-lasting weight loss, it’s often better to focus on losing fat than water weight. 

Like any medication, spironolactone comes with some side effects and risks. Possible side effects include:

• Abdominal cramps or pain

• Diarrhea

• Disruptions to the menstrual cycle

• Enlarged breasts

• Fatigue

• Post-menopausal bleeding

• Reduced sex drive and/or trouble maintaining an erection

In rare cases, there may also be more serious side effects, like impaired kidney function, low blood pressure, flu-like symptoms, blood in stool, and difficulty breathing. Spironolactone may also cause hyperkalemia, which is when potassium levels are too high because of the way it works. 

Spironolactone is considered unsafe in pregnancy, so if you are taking the medication and are of reproductive age, you should be sure you are on reliable contraception. 

If you are taking spironolactone and gaining weight, it’s always a good idea to contact your healthcare provider. They’re best equipped to determine what might be causing this effect and craft a plan to address it. That said, there are many evidence-backed ways to not only stop but also prevent weight gain on spironolactone (and in general). 

Eat a balanced diet

This tip may sound cliche, but it’s a classic for a reason: improving your diet can help you lose weight and keep it off. To best support your goals, keep the following recommendations from the most recent  Dietary Guidelines for Americans in mind:

• Eat more fruits, vegetables, and whole grains (e.g. quinoa). (However, avoid over-consuming high-potassium foods like bananas and potatoes while on spironolactone.) 

• Add lean protein to most meals. Sources of protein include lean meats, legumes, soy protein, eggs, and seafood.

• Limit foods and drinks that are high in sodium, saturated fats, and added sugars. 

• Swap out ultra-processed foods for whole foods whenever possible.

Move your body

While everyone’s journey is different, following a consistent workout routine is crucial for losing and maintaining weight. Meaning, regular exercise can help prevent weight gain on spironolactone. 

The general recommendation, such as that from the Centers for Disease Control and Prevention (CDC), is to do at least 150 minutes of moderate aerobic activity (e.g. biking, brisk walking) per week. On top of this, you should also incorporate muscle-building strength training at least twice per week. Depending on the reason spironolactone is prescribed, exercise may be a complementary treatment for your underlying medical condition. Exercise, for example, can help manage PCOS symptoms and may prevent future cardiac events.

Prioritize quality sleep 

Although sometimes overlooked, getting ample shut-eye is essential for your overall health and wellbeing. It’s also key for preventing and stopping weight gain while taking spironolactone. That’s because sleep plays a critical role in regulating hormones that influence appetite and metabolism. 

Without enough shut-eye, your body will make less leptin (the satiety hormone) and more ghrelin (the hunger hormone), potentially increasing your appetite and leading to overeating. What’s more, reduced sleep can also increase inflammation, a risk factor for obesity and other conditions. This is especially relevant for those with PCOS, as the condition is often associated with chronic low-grade inflammation, which can exacerbate hormonal imbalances and contribute to or worsen symptoms like weight gain.

So how much beauty sleep should you aim for each night? While the exact number depends on your age, most adults should try to catch 7–9 hours of zzz’s per night.  

Manage stress

High levels of cortisol, the stress hormone, has been shown to increase belly fat and heighten the production of glucose (sugar)—two effects that, in turn, can lead to stress-induced weight gain. What’s more, chronically elevated cortisol levels can promote cravings for “comfort foods” (which are typically higher in calories and lack nutrients). This can increase the chances of overeating and, as you probably guessed, weight gain. As if stress didn’t wreak enough havoc on your wellbeing already, it can also increase oxidative stress and inflammation, both of which can contribute to excess weight. 

The good news? There are a myriad of ways you can take care of your mental health, ranging from in-the-moment techniques that can calm your nervous system (e.g. mindfulness exercises, deep breathing) to more comprehensive strategies, such as working with a mental health professional. Other tactics that can help manage stress include journaling and meditation. 

So, can spironolactone cause weight gain? The prescription pill has not been shown to do so, and in some cases, spironolactone may even cause (water) weight loss. Here’s what to keep in mind when it comes to spironolactone and weight gain. 

• The side effect is not listed on the prescribing information for the drug and is considered fairly uncommon. That said, if weight gain on spironolactone does occur, it’s likely due to other causes, such as PCOS, for which the medication is often prescribed off-label.

• While studies have not shown spironolactone to directly cause weight gain, there is scientific evidence that the medication can cause slight, temporary weight loss. This effect is believed to be because of spironolactone’s ability to flush out extra fluids from the body, which can lead you to lose water weight. 

• To prevent and stop weight gain, be it while taking spironolactone or in general, consider lifestyle changes that support healthy weight management, including getting ample sleep, moving your body regularly, and eating a balanced diet. And remember: it’s always a good idea to consult your healthcare provider if you’re experiencing unexpected symptoms, such as weight gain while taking spironolactone, especially when noticed in particular areas such as increased breast tissue. 

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How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

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Current version

December 05, 2024

Written by

Angela Myers

Fact checked by

Beverly Tchang, MD and Raagini Yedidi, MD

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About the medical reviewers

Beverly Tchang, MD

Beverly Tchang, MD, is an Obesity Medicine Advisor for Ro. She is also an assistant professor of Clinical Medicine at Weill Cornell Medicine in New York and triple board-certified in Internal Medicine, Endocrinology, and Obesity Medicine.

Raagini Yedidi, MD

Raagini Yedidi, MD, is an internal medicine resident and medical reviewer for Ro.