Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 8/10/2022
Spironolactone is a prescription medication that’s used to treat a variety of conditions, from acne to hair loss, heart failure and more. Some of these uses for spironolactone are approved by the FDA, while others are for “off-label” use.
Below, we’ve listed some of the uses for spironolactone. We’ve also looked at how and why spironolactone is a useful, effective treatment for each condition.
Spironolactone is a diuretic — a type of medication that causes your body to excrete excess salt and water in your urine.
It’s approved by the FDA as a treatment for, among other conditions, fluid retention caused by several diseases and conditions, including cirrhosis of the liver, kidney disease and heart failure.
These conditions can cause your body to retain more water than normal. If you have fluid retention, you may experience swollen feet, ankles and legs.
Spironolactone works by inhibiting the action of a hormone called aldosterone. This hormone is responsible for conserving sodium within the body. By blocking its effects, spironolactone helps your body expel sodium, drawing excess water out of your body at the same time.
Spironolactone is often referred to as a potassium-sparing diuretic, meaning it causes your body to retain potassium while getting rid of excess water.
Spironolactone’s diuretic effects also make it a helpful treatment for certain forms of high blood pressure, or hypertension. The hormone aldosterone plays a key role in regulating blood pressure.
Spironolactone is sometimes used to treat hypokalemia, or low blood potassium levels. Hypokalemia occurs when your blood potassium level drops below 3.5 mEq/L (3.5 mmol/L). If untreated, this can be a potentially life-threatening issue.
Hypokalemia can occur for a range of reasons, from low potassium intake to use of medications that expel potassium from your body.
People with hypokalemia might feel weakness and fatigue, as well as other symptoms, such as muscle cramps, heart palpitations, tingling, numbness and constipation.
As a diuretic, spironolactone spares potassium while removing extra fluid from the body. Spironolactone is generally considered a safe, effective treatment for hypokalemia.
Although it isn’t approved by the FDA as an acne treatment, spironolactone is sometimes prescribed off-label as a medication for treating hormonal acne.
In addition to inhibiting the effects of the hormone aldosterone, spironolactone is also an androgen blocker that can reduce the effects of androgenic hormones. Androgens cause increased sebum production in the skin, which leads to an increased risk of experiencing hormonal acne breakouts, particularly just before your period.
As an androgen blocker, spironolactone reduces the impact of androgens in your body. This can reduce sebum levels and make you less likely to experience acne breakouts.
Although results from spironolactone aren’t immediate, they are real. In a four-year study, 86 percent of people experienced improvements in their acne after using spironolactone.
In a separate study from 2017, 94 out of 110 women saw improvements in acne after treatment with spironolactone.
Sixty-one of the women who took part in the study reduced their comprehensive acne severity scale (CASS) score to zero, indicating no or barely noticeable acne after treatment.
Spironolactone may cause side effects when used as an acne treatment. For more information, you can read our guide to spironolactone 25 mg.
If you suffer from female hormonal hair loss, your healthcare provider may recommend spironolactone as a treatment option.
As we’ve explained in our guide to female hair loss, the same hormones that cause hair loss in men can cause hair loss in women. In both sexes, it’s the same culprit — a byproduct hormone of testosterone that’s called dihydrotestosterone, or DHT.
By reducing your production of testosterone, spironolactone indirectly exerts an influence on how much DHT is produced in your body, reducing hormonal hair loss in the process.
Because of spironolactone’s effects on testosterone, it isn’t a suitable medication for hormonal hair loss in men. However, it can often be an effective treatment for women who are losing hair due to an androgen-related cause.
In a retrospective study carried out by the UCLA hair clinic, over 70 percent of women with hair loss reported either a mild improvement or an increase in hair thickness after being treated with spironolactone.
A small study of elderly women with hair loss carried out in 2005 produced similar results, with 44 percent of women who received spironolactone or cyproterone acetate (a different antiandrogen) showing signs of hair regrowth, and another 44 percent experiencing no worsening of hair loss.
There’s also some evidence that combination therapy with spironolactone and minoxidil may be effective as a treatment for female pattern hair loss. However, it’s worth noting the researchers also concluded that additional studies with control groups are necessary.
Because spironolactone is an antiandrogen, it won’t work for hair loss that’s caused by stress, diet, thyroid conditions or iron deficiency anemia. However, if you’re losing your hair and think it’s due to a hormonal issue, spironolactone could be worth discussing with your healthcare provider.
Although it isn’t approved by the FDA for this condition, spironolactone is sometimes used off-label as a treatment for the symptoms of polycystic ovary syndrome (PCOS).
Women with polycystic ovary syndrome may have an elevated androgen (e.g. testosterone) level. This can lead to a range of androgen-related symptoms, including hirsutism (excessive hair growth affecting the face and body), acne and weight gain.
If you have PCOS and display one or several of these symptoms, your healthcare provider might recommend spironolactone as a treatment option.
As an antiandrogen, spironolactone can block the effects of androgens and help treat some of the symptoms of PCOS. For example, one study found that spironolactone helped to reduce the growth of facial hair in women with hirsutism caused by PCOS.
Another newer, more comprehensive study found that spironolactone is effective as a treatment for PCOS, particularly spironolactone for facial hair management and menstrual cycle frequency.
Interested in learning more about spironolactone? Our detailed guide to spironolactone and how to safely stop taking spironolactone for acne covers everything you need to know, from how spironolactone works to side effects, drug interactions, frequently asked questions and more.