Spironolactone Side Effects: An Overview

If you’ve been researching hair loss treatments, you may have come across spironolactone. The prescription drug is the most used antiandrogen treatment for female pattern hair loss in the U.S., but there are spironolactone side effects to be aware of.

It’s actually not recommended for the treatment of hair loss or acne in men because of some of those side effects.

So, what are the cons of taking spironolactone if you’re a man? Great question. We’ll answer it in more detail below — but for starters, spironolactone can lead to enlarged breast tissue, cause high potassium blood levels, and make you pee a lot.

Besides the possible spironolactone adverse effects, we’ll dive into what spironolactone is used for to treat in men and women, plus hair loss treatment alternatives to spironolactone that are safe for men.

Spironolactone is a diuretic (also known as a water pill) commonly used to treat high blood pressure and heart failure. It’s not recommended as a treatment for male pattern hair loss (aka androgenetic alopecia), but that doesn’t mean it’s never used by men.

So, what is spironolactone used for in men? It’s FDA-approved to treat heart failure, hypertension (high blood pressure), and primary hyperaldosteronism (when the adrenal glands produce too much of the hormone aldosterone) in both men and women.

Since it’s a water pill, it can also treat fluid retention (edema) in patients with congestive heart failure, liver cirrhosis, or a kidney disorder known as nephrotic syndrome.

Spironolactone can still cause side effects in men taking it for one of its FDA-approved uses. But in those situations, the benefits may outweigh the risk of potential side effects.

Spironolactone (brand name Aldactone®) is sometimes prescribed off-label for women experiencing hair loss, acne, and hirsutism (male pattern facial hair in women). It’s also occasionally used as part of gender-affirming therapy.

The versatile medication works for all these things because it slows testosterone production. Most research on spironolactone and hair loss is done on women simply because it’s generally not used by men for this purpose.

When it comes to pattern balding, less testosterone is actually a good thing because DHT (short for dihydrotestosterone) — the main hormone responsible for female and male pattern baldness — is a byproduct of testosterone. So less testosterone means less DHT.

Seems like a win, right? Unfortunately, not exactly.

Why Spironolactone Isn’t Recommended for Men’s Hair Loss

Spironolactone technically could be an effective treatment for male pattern baldness. Some research suggests that topical spironolactone is safer than its oral counterpart and could be a suitable hair loss medication for both male and female patients. However, no (or low) testosterone is generally not a good thing for men.

Precisely because of its potentially drastic effect on male hormones (the very thing that would make it helpful in hair loss), spironolactone isn’t recommended for hair loss or any other off-label use in men.

Fortunately, other hair loss treatments are effective for male pattern baldness without the feminizing side effects — more on these below.

Like all medications, spironolactone has side effects, but they won’t affect every person.

In one study done on women taking spironolactone, 33 percent reported an adverse event (aka a side effect), and 3.8 percent discontinued spironolactone because of said event.

While it’s hard to say for sure, we can expect that even more people would have withdrawn from the study had it included men. Why? Certain side effects like breast growth are likely less tolerable in men than women.

Spironolactone side effects in men and women include:

• Fatigue

• Increased urination

• Dizziness

• Hives

• Headache

• Nausea

• Vomiting

• Diarrhea

• Irregular menstrual cycles in women

• Breast tenderness

• Breast growth

• High blood potassium levels

• Low sodium levels

• Dehydration

• Stomach bleeding or ulcers

• Confusion

• Loss of balance

• Rashes

• Kidney problems

• Electrolyte imbalances

• Loss of libido

• Irregular heartbeat

The above list is understandably a little daunting. If you feel like you just heard the side effects rattled off quickly at the end of a drug commercial, don’t worry. We’ll dive a little deeper into some of the more pronounced spironolactone side effects men and women should know about.

High Potassium Levels

Spironolactone is a potassium-sparing diuretic. This means it prevents the body from absorbing too much salt while keeping potassium levels from getting too low.

These types of drugs can be key in managing conditions like hypertension, cirrhosis, and heart disease. But on the flip side, a major side effect of spironolactone is hyperkalemia — high potassium levels in the blood. This can be potentially life-threatening if left untreated.

For this reason, your provider may want to do regular blood tests to check potassium levels. They also might tell you to avoid potassium supplements and salt substitutes (which contain high levels of potassium).

In some cases, you might be told to avoid eating too many potassium-rich foods, like bananas or leafy greens.

If you have a condition that causes high potassium levels, like Addison’s disease, you shouldn’t take spironolactone, as it could lead to dangerously high potassium levels.

Breast Growth and Tenderness

As noted, spironolactone is a well-known cause of gynecomastia (development of breast tissue in men). This is the most commonly reported adverse reaction associated with Aldactone.

The medication suppresses androgens (male hormones) and can increase the metabolic clearance of testosterone (how much of the hormone is released from your body through fluids).

That means you have less testosterone in your body, which can contribute to breast development and other feminine characteristics. It also increases estrogen levels. Women taking spironolactone may notice breast pain or growth.

In a 2007 study on people taking spironolactone for ambulatory heart failure, 25 percent stopped using it due to adverse outcomes. Of the 25 percent, 5.3 percent of men stopped because of gynecomastia.

Gynecomastia isn’t a serious medical condition. Still, it can be painful, unpleasant, and all-around difficult to cope with.

Development of Feminine Characteristics

Spironolactone is often used by transgender women undergoing gender-affirming hormone therapy (GAHT). Since it blocks male sex hormone receptors and lowers testosterone, it can lead to other feminine characteristics, like facial feminization.

This is crucial for transgender people but can be distressing for cisgender men.

Spironolactone isn’t recommended for women who are pregnant, as it may interfere with male fetal development. For instance, some evidence suggests it can cause feminization of male fetuses, including underdeveloped reproductive organs or ambiguous genitalia (not clearly male or female).

But most of these studies have been done on animals. As of 2022, there was only one known case of spironolactone-induced sexual ambiguity in a human infant.

Electrolyte Imbalances

Spironolactone can increase potassium levels and decrease sodium levels in the blood. Sodium and potassium are both electrolytes. (Fun fact: Electrolytes conduct electricity when dissolved in water, and your muscles need that electricity to contract).

Electrolytes (which also include magnesium, calcium, bicarbonate, and chloride) are also responsible for helping maintain fluid levels in the body.

An imbalance can set off a cascade of other side effects, including muscle weakness, cramps, dehydration, dizziness, headaches, rapid heart rate, fatigue, and confusion.

Low Libido

Because it lowers levels of testosterone, low libido (reduced sex drive) can be a side effect of spironolactone. Research also shows that men using spironolactone may experience mild impotence (erectile dysfunction).

Upset Stomach and Indigestion

Even if it seems manageable, you’ll want to let your provider know if you have any stomach issues or cramping while taking spironolactone. In rare cases, it can cause stomach bleeding or ulcers.

Frequent Urination

Diuretics like spironolactone release excess water and sodium from the body. This is good news for folks with swelling and high blood pressure, but it also means you’ll be running to the bathroom a lot more.

Some people prefer to take spironolactone in the morning so they don’t wake up at night to pee.

Fatigue

Fatigue may be more intense in the first few weeks of spironolactone treatment or when upping your dose. Changes in blood pressure and electrolyte levels can cause tiredness as your body adjusts.

Renal Dysfunction

Renal function is how well the kidneys are working. Spironolactone can cause a deterioration of kidney function, especially in the first three months of use.

In the study mentioned earlier on patients with ambulatory heart failure, 25 percent stopped using spironolactone because of side effects. And of the 25 percent, 14.5 percent reported renal function deterioration as the reason for stopping.

All that said, if you have kidney disease or liver disease, you may not be a good candidate for spironolactone.

Low Blood Pressure (Hypotension)

Spironolactone can cause a drop in blood pressure, particularly when going from sitting to standing (postural hypotension). As fluid releases from the body, pressure on blood vessels decreases, causing blood pressure to drop.

This can be a good thing for those with high blood pressure. But if you’re taking spironolactone off-label and your blood pressure is on the low side, it might lower it even more. This can lead to things like lightheadedness, dizziness, or fainting.

To learn more about spironolactone side effects in women, like spotting or irregular menstrual cycles, check out our Hers guide to spironolactone for hair loss in women.

Although rare, spironolactone has potentially serious side effects. Contact a healthcare professional if you experience any symptoms of spironolactone overdose or allergic reaction, including:

• Drowsiness

• Mental confusion

• Rash with both flat and raised parts

• Nausea

• Vomiting

• Dizziness

• Diarrhea

Other severe side effects of spironolactone that should be discussed with your provider include:

• Racing heart or abnormal heartbeat

• Fainting

• Blood in the stool

• Yellowing of the eyes or skin

You should also consult your healthcare provider before taking spironolactone with other drugs.

It can have potential drug interactions with medications. This includes NSAIDs (non-steroidal anti-inflammatory drugs), such as ibuprofen and naproxen. You’ll also want to avoid taking it with lithium, heparin, trimethoprim, amiloride, eplerenone, angiotensin II receptor blockers (ARBs), ACE inhibitors, or digoxin.

Fortunately, other hair loss treatments for men work without causing the side effects that come with spironolactone. Here are a few of our favorite science-backed hair loss medications for men.

Finasteride

Finasteride is an FDA-approved prescription medication for the treatment of male pattern baldness. It works on male hormones but doesn’t affect testosterone levels. Instead, it blocks the conversion of testosterone to DHT (which, remember, is the byproduct of testosterone that causes hair loss).

Some research on men taking finasteride for benign prostatic hyperplasia (a higher dosage than would be prescribed for hair) suggests that the medication actually causes a modest increase in testosterone levels.

But it’s not known to cause gynecomastia. Also, finasteride isn’t prescribed for most women.

Minoxidil

Minoxidil dilates blood vessels, bringing blood, oxygen, and nutrients to the scalp to support healthy hair growth.

We offer a topical minoxidil foam and a liquid minoxidil solution (both at 5% strength). They work the same way, but those with longer hair may prefer the liquid solution’s dropper applicator.

In rare cases, some people may experience redness or irritation where they apply minoxidil. It’s unclear exactly what causes this, but some researchers think it’s because of the ingredient propylene glycol (an alcohol).

The foam doesn’t contain this ingredient, so it’s a good choice for sensitive skin and those who’ve had a reaction to the liquid.

Using Minoxidil and Finasteride Together

You can also pair minoxidil and finasteride, either by using them separately or with a product that contains both, like our topical finasteride & minoxidil spray.

A 2019 meta-analysis found that the combo of finasteride and topical minoxidil is more effective and just as safe as using one or the other on its own.

While spironolactone dangers are rare, the drug does have side effects to be aware of.

Here’s what to keep in mind:

• Side effects of spironolactone range from mild to severe and include breast growth, fatigue, kidney problems, high blood potassium levels, and low sodium levels — to name a few.

• If you experience any side effects or just feel weird while taking spironolactone, it’s best to seek medical advice from a healthcare provider. They can help you discern what a major side effect of spironolactone is versus more common side effects.

• Spironolactone isn’t recommended for treating hair loss in men because of its feminizing side effects. But other hair loss treatments like finasteride and minoxidil are FDA-approved specifically for treating male pattern baldness.

Our range of hair loss treatment products includes FDA-approved medications, volumizing shampoo, thickening shampoo with saw palmetto, and biotin gummies.

If you’re ready to take a step toward hair loss treatment, start with an online hair loss consultation.

You can also explore your options with our guide to the best treatments for thinning hair.