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Spironolactone — spiro, as we call it — is my favorite oral treatment for women with hormonal acne, and it is fine to stay on long term. If an oral medication for acne worries you, you can start at a very low dose just to see how you do. The main downsides are dizziness in some women and peeing more. Don't take a high dose at night, or you'll be up to pee.
— Dr. Schwarz, Board Certified Dermatologist
Key Facts
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| Also called | Aldactone, CaroSpir |
| Drug class | Aldosterone blocker with anti-androgen effects |
| Taken as | Tablet or liquid |
| Typical course | A year or more, often longer |
| Time to work | About 3 months |
| Prescription only | Yes |
What It Is
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Spironolactone is a tablet developed as a diuretic, a drug that makes the kidneys pass more water and salt. It treats heart failure, high blood pressure and fluid retention. It also blocks androgen receptors, which is what makes it useful in acne. That use is off-label but long established and guideline-supported in adult women.
How It Works
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Androgens make oil glands produce more oil, and more oil means more clogging and more inflammation. Spironolactone blocks androgens at the gland and lowers how much testosterone the body makes, so oil production falls. Skin gets less greasy before spot counts drop.
It does not only work if your hormone tests are abnormal. Most women who respond have normal levels. What matters is how sensitive the oil gland is, and no blood test measures that.
Acne treatments do not all do the same thing. Here is where Spironolactone acts, and what the others do instead.
Pick a treatment
Skin basics
Benzoyl peroxide releases oxygen inside the pore, and the bacteria involved in inflamed acne cannot live in it. It is the fastest of these on red, sore spots, and the one thing that stops acne bacteria becoming resistant to antibiotics.
Salicylic acid dissolves in oil, so it gets down inside the pore rather than sitting on the surface, and loosens the plug of dead skin and sebum blocking the way out. That suits blackheads and whiteheads more than deep, sore spots.
Retinoids change how the pore lining sheds, so plugs stop forming in the first place — which is why they prevent spots rather than treat the ones already there. Given months they also slow pigment reaching the surface and push fibroblasts to build collagen.
Azelaic acid does three things at once: loosens the plug in the pore, reduces the bacteria in it, and calms the pigment cells that leave a dark mark behind. That combination makes it useful on deeper skin tones, where the mark often outlasts the spot.
Niacinamide turns oil production down a little and interrupts pigment being handed to the cells above. The evidence for clearing spots is thin; it earns its place for the marks left behind, and for making stronger actives easier to tolerate.
Clindamycin is an antibiotic that quiets the bacteria in an inflamed pore. Used on its own it stops working within months as they adapt, so it is always paired with benzoyl peroxide or a retinoid.
Spironolactone blocks the hormone signal telling oil glands how much to make. It works on the pattern rather than the individual spot, over three to six months, which is why it suits deep jawline acne that flares with the cycle.
Isotretinoin shrinks the oil glands themselves, and much less oil means less of everything downstream: fewer plugs, fewer bacteria, less inflammation. It is the only acne treatment that often keeps working after the course ends.
The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.
The cells that make pigment. They sit along the base of the epidermis and hand melanin to the cells around them, which is what gives skin its colour. Dark marks, melasma and the patch left behind by a spot are all these cells making more than usual.
A narrow tube running from the surface down into the skin, with an oil gland at the bottom of it. Oil travels up and out. When the tube blocks, what is behind it has nowhere to go — which is where blackheads and spots start.
Makes sebum, the oil that keeps the surface soft and stops water escaping. How much it makes is set by hormones, not by how often you wash — which is why scrubbing does not fix oily skin.
Cutibacterium acnes lives in the pores of everyone with skin. It is not an infection and it is not a hygiene problem. It only causes trouble when a pore blocks and it multiplies in the oil trapped behind it.
The scaffolding in the dermis that keeps skin firm and springy. It is built by fibroblasts and broken down by age, sun and smoking. Lines and looseness are collagen lost faster than it is replaced.
The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.
What It Treats
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Not the Best For
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Forms
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Strengths
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Tablets are often split at the start.
Dose
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The dose depends on tolerance and blood pressure more than weight. Kidney function sets the ceiling.
How to Take It
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When to take it: Once daily, with or without food, though food reduces nausea. Take it in the morning — it increases urination for the first week or two. Some doctors split the dose. Drink to thirst; forcing water on a diuretic just means more trips to the bathroom.
If you miss a dose: Take it when you remember, the same day. If it is nearly the next day, skip it.
What to Expect
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Side Effects
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Side effects are common at higher doses and mostly manageable. The dangerous ones are rare in healthy young women.
Common — expected, and they settle
- Peeing more Most noticeable in the first few weeks.
- Irregular or missed periods Dose-related, and often better on a lower dose.
- Breast tenderness Sometimes slight enlargement with it.
- Lightheadedness Usually eases as your body adjusts.
Tell your doctor — worth a call, not an emergency
- Periods that stop completely Not just irregular.
- Dizziness that does not settle Especially when you stand up.
- Ongoing breast pain or a new lump Worth getting looked at.
- Any new drug that raises potassium Tell whoever prescribes it that you take this.
Stop and get care
- Muscle weakness with numbness or tingling Can be a sign of high potassium.
- A slow or irregular heartbeat Same reason. Get checked the same day.
- Confusion Uncommon in healthy young people, but serious.
What to Avoid
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- Potassium supplements and salt substitutes Most salt substitutes are potassium chloride, and spironolactone already raises potassium.
- Daily anti-inflammatories Ibuprofen and similar drugs taken regularly raise potassium and cut blood flow through the kidneys. An occasional headache tablet is different.
- Licorice in medicinal amounts It works directly against the drug. Licorice root teas and supplements, not ordinary sweets.
- Alcohol No direct interaction, but it adds to the lightheadedness early on.
Monitoring
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Blood pressure is checked before starting. For healthy women under about 45 with normal kidneys and no interacting medicines, current guidance supports skipping routine repeated potassium tests — abnormal results in this group are rare and rarely meaningful. Potassium and kidney function are checked over 45, with kidney or heart disease, or on drugs that raise potassium.
This is a drug people stay on for years. What drifts is kidney function with age and the medicine list, so the decision gets revisited. A yearly review of dose, blood pressure and other medicines is usual.
If You Stop
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No withdrawal, no taper needed at acne doses. Oil production returns to its previous level over weeks, and acne usually comes back within two to four months. Stopping and restarting is possible, but each restart means waiting three months again. Most people who come off step down to the lowest dose that holds the result.
Cost
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Generic spironolactone is cheap and widely available. Some insurers query acne as an off-label use, but the cost rarely blocks treatment. The liquid form costs far more than tablets.
Ask Your Doctor
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How It Compares
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Myths
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- "It causes breast cancer." The tumor warning comes from rats on very high doses for long periods. In people, a cohort study of 420 women treated for acne, hair loss and hirsutism found no increase in breast or gynecologic cancers over five years.
- "You need regular potassium tests." For a healthy young woman on it for acne, routine testing has not been shown useful — a study of 974 patients found raised potassium at the same rate as in women not taking it. Monitoring is for kidney or heart problems, or drugs that raise potassium.
- "It is a hormone." It is a diuretic that blocks androgen receptors, not estrogen, progesterone or testosterone.
- "You will be in the bathroom all day." At acne doses the diuretic effect is mild and settles early.
Questions Patients Ask
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Do I need regular blood tests?
A healthy woman under about 45 with normal kidneys and no interacting medicines does not need routine potassium testing. If you are older, or have kidney or heart disease, or take drugs that raise potassium, testing is appropriate.
Do my hormone levels have to be abnormal for it to work?
No. Most women who respond have normal blood tests. What matters is oil gland sensitivity, which is not measurable.
Will it stop my periods?
It can make them irregular at higher doses. A combined contraceptive pill alongside usually prevents this.
Can men take it for acne?
Generally avoided — at acne doses it commonly causes breast enlargement and tenderness. Clascoterone cream is the alternative.
What about the old cancer warning?
Those findings came from rats on very high doses. Human studies have not shown a matching risk at acne doses.
References
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- Reynolds RV, Yeung H, Cheng CE, et al. Guidelines of care for the management of acne vulgaris. J Am Acad Dermatol. 2024. — American Academy of Dermatology, 2024
- Nast A, Al Wattar BH, Beylot Barry M, et al. Update of the EuroGuiDerm evidence-based guideline for the treatment of acne-Short version. Journal of the European Academy of Dermatology and Venereology : JEADV. 2026. — Journal of the European Academy of Dermatology and Venereology : JEADV, 2026
- Williams B, MacDonald TM, Morant S, et al. Spironolactone versus placebo, bisoprolol, and doxazosin to determine the optimal treatment for drug-resistant hypertension (PATHWAY-2): a randomised, double-blind, crossover trial. Lancet (London, England). 2015. — Lancet (London, England), 2015
- Tian Z, Vollmer Barbosa C, Lang H, et al. Efficacy of pharmacological and interventional treatment for resistant hypertension: a network meta-analysis. Cardiovascular research. 2024. — Cardiovascular research, 2024
- Carey RM, Calhoun DA, Bakris GL, et al. Resistant Hypertension: Detection, Evaluation, and Management: A Scientific Statement From the American Heart Association. Hypertension (Dallas, Tex. : 1979). 2018. — Hypertension (Dallas, Tex. : 1979), 2018