Spironolactone side effects in women: Risks & what to expect

If you struggle with acne or hirsutism and have tried every possible solution, you’ll probably be familiar with spironolactone.It’s a medication that’s been used for decades and is commonly prescribed off-label to help reduce excess androgen activity, the hormone imbalance often behind these symptoms.

For many women, spironolactone can significantly improve hormonal acne and reduce unwanted hair growth over time.

But like every medication, Spironolactone has side effects that range from mild to severe. You need to know all possible side effects if you consider using one. And as with any treatment, you should talk to your doctor first to make sure it’s the right fit for you.

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What Spironolactone Is and What It Was Meant to Be

Spironolactone was originally developed and approved in the late 1950s and early 1960s as a potassium-sparing diuretic. That means it helps the body eliminate excess water and sodium without losing potassium, unlike traditional diuretics that often drain the body of it. It's taken orally, available in tablet and suspension forms, and is sold under various trade names, including Aldactone, CaroSpir, and Spiractin in some countries.

It works by antagonising aldosterone, a hormone produced by the adrenal glands, that regulates salt and water balance in the body. When aldosterone levels rise, the kidneys retain sodium and water and excrete potassium. This effect is helpful if your blood pressure is low, but it is dangerous when your body already has too much fluid or if your heart is struggling to function properly.

By blocking aldosterone, spironolactone produces an opposite effect on the kidneys, making it useful in treating conditions like congestive heart failure, primary hyperaldosteronism^, and oedema caused by liver cirrhosis or kidney disease.

With time, researchers began to notice another striking effect of Spironolactone that had nothing to do with fluid retention or blood pressure. It was observed to cause gynecomastia in men placed on the drug, a side effect linked to androgen receptor blockade. This opened up a completely different path for spironolactone use, especially in women.

What is Spironolactone Use in Women?

1. Hirsutism

In conditions like polycystic ovary syndrome (PCOS), where women may experience hirsutism (thicker or darker hair growth on the face, chest, or back) due to higher levels of androgens, spironolactone proves useful. It binds to the androgen receptors in hair follicles, blocks testosterone from binding, and reduces excessive hair growth. It usually takes 6 to 12 months to see the results, but the long-term benefits are worth it.

2. Hormonal Acne

Spironolactone is one of the most common prescriptions for stubborn adult acne, particularly along the jawline and chin. It works just like it does with the hair follicles, but this time, on the sebaceous gland, reducing oil production in the skin. Less oil, fewer clogged pores, and fewer breakouts.

In women whose acne didn’t respond to over-the-counter treatments or even antibiotics, spironolactone often made a visible difference.

3. PCOS Symptoms Management

PCOS doesn’t just bring unwanted hair or acne; it also comes with irregular periods and hormone-driven weight changes. Though not a cure for PCOS, Spironolactone helps reduce some of its more visible symptoms by reducing effects of androgen.  For effective management, Spironolactone is used in combination with other hormone regulators and birth control pills.

4. Androgenic Alopecia (Hair loss)

Spironolactone is sometimes used off-label for pattern hair loss in women. It works in the opposite way, helping with hirsutism by blocking testosterone’s shrinking effect on scalp hair follicles. Though evidence is still developing, a small 2023 study showed improvement in hair density in about 56.6% of women following prescribed spironolactone use.

Spironolactone Side Effects 

The side effects of spironolactone vary. Some can be mild, others disruptive, and a few potentially serious, depending on the dosage. While many women tolerate the drug well, you can experience unexpected changes without warning. These changes include:

• Menstrual Irregularities

A common complaint among women on spironolactone is that their period becomes unpredictable. This can show up as irregular bleeding (metrorrhagia), missed periods (amenorrhea), or unexpected spotting in the middle of a cycle. These changes often depend on the dose.

Studies show that 13% to 33% of women experience menstrual irregularities while on spironolactone, and that number can rise to over 70% in women taking 200 mg or more per day.

Combining spironolactone with oral contraceptives doesn’t just offer birth control protection; it also helps regulate bleeding patterns. This is why many dermatologists and endocrinologists prescribe the two together, especially for women using spironolactone to manage acne or hirsutism.

• Breast Tenderness and  Enlargement 

Some women report breast tenderness after starting spironolactone, and in fewer cases, a slight increase in breast size. This is likely due to the drug’s mild estrogen-like effects and its ability to block androgens.

Clinical studies estimate that 5% to 17% of women experience breast tenderness, and about 2% may notice some breast enlargement. These changes tend to be mild and reversible once the medication is stopped or the dose adjusted; the symptoms usually go away on their own.

• Sexual Side Effects 

Reduced androgen levels can lead to lower libido, particularly in women already on hormonal contraceptives. Some women also report vaginal dryness or a general disinterest in sex while on Spironolactone. This is rarely discussed during consultations, but it can significantly affect quality of life.

• Pregnancy Risks 

Spironolactone should not be taken during pregnancy, especially in the first trimester. Studies in animal models proved that spironolactone can cause feminisation of male fetuses, and while human data is limited, the potential risk is serious enough that it's classified as pregnancy category C by the FDA.

Women of childbearing age are usually advised to use contraception while taking the drug. If you're trying to conceive, spironolactone is typically paused or replaced with a safer alternative.

• Mood Changes and Mental Health Effects 

Some women experience mild nausea, bloating, or stomach upset, especially in the first few weeks of taking spironolactone. These symptoms are usually short-lived and can often be minimized by taking the drug with food.

Clinical studies peg these gastrointestinal symptoms in about 1.7% to 3.6% of patients taking spironolactone. This is no reason to stop the drug, but worth watching out for.

• Potassium Build-up (Hyperkalemia)

As a potassium-sparing diuretic, one expected side effect of spironolactone is hyperkalemia. This risk increases when combined with potassium supplements or drugs like ACE inhibitors. However, in healthy young women, the likelihood of serious hyperkalemia is low. 

A 2015 study in JAMA Dermatology involving over 1,200 women using spironolactone for acne found no significant rise in dangerous potassium levels. As a result, many dermatologists no longer routinely monitor potassium in healthy women under 45. For those with kidney disease, other medical conditions, or over age 45, regular potassium checks are still recommended.

• Fatigue, Dizziness, and Headaches 

Since spironolactone is a diuretic, it lowers blood pressure and alters fluid levels, leaving some women feeling tired, lightheaded, or foggy (especially in the first weeks of treatment). These effects tend to be less common (around 1.5-3.4%) and may not always be tied to the dose. It also improves after the body adjusts to the medication, but if they persist, switch to a lower dose or another medication.

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Final Thoughts

Spironolactone is not just another prescription – it's a hormone-influencing medication with real effects, both beneficial and potentially disruptive. But when used correctly, it can be a powerful ally.

If you’re considering using spironolactone or are already on it, understanding how it works and what to watch for is the smartest way to get the results you want while protecting your health in the process. And as with any hormone-related treatment, it should be used only under medical guidance.

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