Is spironolactone effective for hirsutism in PCOS?

Yes. Doses of 50 to 200 mg/day of spironolactone significantly reduce the Ferriman-Gallwey score after 6 months of treatment. A Cochrane review (Swiglo et al.) and several RCTs in PCOS demonstrate a 30 to 50% reduction in hirsutism score compared to placebo, comparable to cyproterone acetate at equivalent doses. Response is dose-dependent and requires 3 to 6 months for proper assessment.

Is cyproterone acetate available in the United States?

No. Cyproterone acetate is not FDA-approved and is not available in the United States. It remains available in Canada, the UK, Australia, and most European countries. In the US, spironolactone is the most widely used anti-androgen for PCOS-related hirsutism and acne, typically at doses of 50–200 mg/day. Patients in the US should not seek to obtain cyproterone acetate from foreign sources without medical supervision.

What is the actual meningioma risk with cyproterone acetate?

The landmark JAMA 2021 study (Weill et al., Inserm, n = 253,777 women) showed a 6.6-fold increased risk of meningioma in women taking cyproterone acetate at doses ≥ 10 mg/day for more than one year. This risk is dose-dependent and duration-dependent: it is very low at the 2 mg dose (Diane-35) but increases significantly from 10 mg/day (used for severe hirsutism). EMA updated the SmPC in 2020: contraindicated if prior meningioma, and discontinuation recommended if meningioma detected.

Does spironolactone require contraception in PCOS?

Yes, absolutely. Spironolactone is teratogenic — it can feminize the genitals of a male fetus (anti-androgen). Effective contraception is mandatory throughout treatment and for at least one month after stopping. In practice, a combined oral contraceptive pill is often co-prescribed with spironolactone, which also improves control of hirsutism and acne.

Can spironolactone raise potassium levels?

Yes. Spironolactone is an aldosterone antagonist and inhibits renal potassium excretion. A potassium check (basic metabolic panel) is recommended at treatment initiation and after 1 month. In practice, significant hyperkalemia is rare in young women with normal kidney function, but remains a monitoring point — especially if the patient takes other potassium-sparing medications (ACE inhibitors, ARBs, NSAIDs).

How long before spironolactone works for PCOS acne?

Spironolactone acts progressively on hormonal acne. Most patients observe noticeable improvement after 3 to 4 months of treatment. Maximum effect is generally achieved after 6 to 12 months. The usual dose for PCOS acne is 50 to 100 mg/day, with doses up to 200 mg for more resistant cases or hirsutism.

Can spironolactone and cyproterone acetate be taken together?

No, this combination is not recommended. Both molecules are anti-androgens and their combination provides no demonstrated benefit but increases the risk of side effects (hyperkalemia, hypotension, hormonal disruptions). In clinical practice, one or the other is chosen based on the patient's profile and available formulations in their country.

Are there alternatives to anti-androgens for hirsutism in PCOS?

Yes. Alternatives include: (1) combined oral contraceptives (estrogen-progestin pills) that reduce androgen production via gonadotropin suppression; (2) eflornithine cream (Vaniqa) which inhibits facial hair growth locally; (3) laser hair removal or intense pulsed light — non-pharmacological but effective for permanent reduction; (4) finasteride (5 mg) which inhibits 5-alpha-reductase, with less data specific to PCOS.

Evidence review · updated 18 May 2026

Spironolactone vs Cyproterone Acetate for PCOS / PMOS: Which Anti-Androgen to Choose?

Both drugs block androgen receptors — but their safety profiles diverge sharply. Cyproterone acetate at doses ≥ 10 mg/day carries a 6.6× meningioma risk (JAMA 2021, EMA 2020). Spironolactone has no such signal. Here is what the evidence shows, the correct doses, and how to choose for PCOS/PMOS.

Information, not a diagnosis. This page provides general guidance. It does not constitute a diagnosis and does not replace a personalised medical consultation.

Quick Verdict

Spironolactone (50–200 mg/day): first-choice anti-androgen for PCOS in most countries where it is available. Proven efficacy on acne and hirsutism, favorable safety profile, low generic cost, no meningioma signal.
Cyproterone acetate ≥ 10 mg/day: effective, but meningioma risk × 6.6 (JAMA 2021). Reserved for refractory cases, shortest duration possible, neurological surveillance if prolonged use.
Diane-35 (cyproterone 2 mg): meningioma risk not significantly elevated at this dose, but restricted use in several countries. Must not be prescribed as a standalone contraceptive.
Both require strict contraception (teratogenicity for spironolactone; built-in for Diane-35).
Note for US patients: cyproterone acetate is not FDA-approved and not available in the US. Spironolactone is the standard anti-androgen option.

Mechanism of action

Hyperandrogenism — elevated testosterone, DHEA-S, or other androgens — is present in 60 to 80% of PCOS/PMOS cases and drives acne, hirsutism (excess hair growth), and androgenic alopecia. Two categories of drugs can counteract these effects: anti-androgens (which block androgen receptors or inhibit their synthesis) and combined oral contraceptives (which reduce ovarian androgen production via gonadotropin suppression). Spironolactone and cyproterone acetate both belong to the anti-androgen category.

Spironolactone

Spironolactone is primarily an aldosterone antagonist(potassium-sparing diuretic), but it also exerts potent anti-androgenic activity through a dual mechanism. First, it competitively blocks androgen receptors in target tissues (hair follicles, sebaceous glands), preventing testosterone and DHT from binding. Second, it partially inhibits 17-hydroxylase and 17,20-lyase, two enzymes of ovarian and adrenal steroidogenesis, reducing endogenous androgen production.

At anti-androgenic therapeutic doses (100–200 mg/day), spironolactone also exerts a mild diuretic effect (increased urine output, modest blood pressure reduction). This diuretic effect can be beneficial in women with PCOS and mild hypertension, but may cause dizziness on standing (orthostatic hypotension) and leg cramps early in treatment.

Cyproterone acetate

Cyproterone acetate (CA) is a potent anti-gonadotropic progestogenwith strong anti-androgenic activity. Its main mechanism: it blocks androgen receptors with higher affinity than spironolactone, and exerts marked gonadotropin suppression (reduction of LH and FSH) via its central progestogenic action, which drastically reduces ovarian androgen production. This dual mechanism (peripheral blockade + central suppression) explains its high efficacy, particularly on severe hirsutism.

At doses ≥ 10 mg/day (high-dose formulations: Androcur 50 mg, sometimes used off-label for severe hirsutism), cyproterone acetate accumulates extensively in tissues with an effective half-life of several days to weeks. This accumulation is now linked to the meningioma risk identified in the EMA 2020 review.

Mechanism	Spironolactone	Cyproterone Acetate
Androgen receptor blockade	Yes (competitive antagonist)	Yes (high affinity)
Inhibition of steroidogenesis	Partial (17-hydroxylase)	Yes (progestogenic effect)
Gonadotropin suppression (LH/FSH)	No	Yes (strong)
Diuretic effect	Yes (aldosterone antagonist)	No
Progestogenic activity	Weak	Strong

Clinical studies

Spironolactone in PCOS — RCT evidence

Spironolactone has solid evidence in the management of PCOS hyperandrogenism. The Cochrane review on anti-androgens in PCOS (Swiglo et al.) analyzes multiple RCTs and concludes that spironolactone is significantly effective for hirsutism versus placebo.

Spironolactone 100 mg vs placebo (6 months): reduction in Ferriman-Gallwey score of -4.8 points (95% CI: -7.1 to -2.5), p < 0.001. Source: Moghetti et al., Journal of Clinical Endocrinology & Metabolism, 2000.
Spironolactone 100 mg vs cyproterone acetate 12.5 mg: comparable efficacy on Ferriman score at 12 months. Spironolactone had a better tolerability profile. Source: Erenus et al., Fertility and Sterility, 1994.
Spironolactone 50–200 mg for PCOS acne: multiple series show a 50 to 70% reduction in inflammatory lesions after 3–6 months. Response is clearly dose-dependent.

Cyproterone acetate — the meningioma signal (EMA 2020, JAMA 2021)

The most important regulatory decision of the last decade regarding cyproterone acetate was the EMA 2020 reassessment, conducted following multiple French and European pharmacovigilance signals. EMA concluded that cyproterone acetate at doses ≥ 10 mg/day was associated with an increased risk of intracranial meningioma, and updated the Summary of Product Characteristics (SmPC) for all European formulations.

This finding was confirmed and quantified by the landmark epidemiological study: Weill A et al., JAMA 2021 (Inserm, cohort study using French SNDS data, n = 253,777 women exposed to cyproterone acetate, median follow-up 7.5 years):

Risk of operated or irradiated meningioma: × 6.6 (HR = 6.6; 95% CI: 5.5–7.9) in women taking ≥ 10 mg/day compared to unexposed women.
Risk is dose-dependent and duration-dependent: increases proportionally with cumulative dose.
At the 2 mg dose (Diane-35): meningioma risk was not significantly increased in this study.
After discontinuation, risk gradually returns toward baseline over several years.

Following this study, multiple countries tightened prescribing guidelines: neurological examination recommended if personal or family history of meningioma, immediate discontinuation if meningioma diagnosed, regular reassessment of indication.

Regulatory status by country

Availability of cyproterone acetate varies significantly by country:

United States: not FDA-approved, not available.
European Union / UK: available with restrictions; doses ≥ 10 mg/day require updated informed consent following EMA 2020.
Australia: available (TGA-approved); Diane-35 available with restrictions similar to Europe.
Canada: Diane-35 available; Androcur (50 mg) available for prostate cancer indication.

Detailed comparison table

Criterion	Spironolactone	Cyproterone Acetate
Main mechanism	Aldosterone antagonist + AR blocker	AR blocker + LH/FSH suppression
Acne efficacy	++ (50–200 mg/day)	++ (2–12.5 mg/day)
Hirsutism efficacy	++ (100–200 mg/day, results at 6 months)	+++ (faster at higher doses)
Approximate monthly cost	$10–30 USD (generic)	Not available in USA; varies by country
Main side effects	Diuresis ↑, dizziness, rare hyperkalemia, spotting	Weight gain, fatigue, low libido, thrombosis risk
Meningioma risk	No known signal	× 6.6 at ≥ 10 mg/day (JAMA 2021, EMA 2020)
Contraception required	Yes (teratogenic)	Built-in if Diane-35; otherwise yes
US availability	Yes (prescription)	Not available (not FDA-approved)
Major contraindications	Renal insufficiency, hyperkalemia	Prior meningioma, severe liver disease
FDA/EMA approval for PCOS	No (off-label)	Not applicable in US; off-label in EU

Which treatment for your profile?

Profile 1 — Hormonal acne and/or moderate hirsutism with need for contraception

A combined oral contraceptive as first line reduces ovarian androgen production and often suffices for moderate cases. If insufficient after 6 months, spironolactone 50–100 mg/day in combination with the pill is the standard approach. This combination optimizes anti-androgenic efficacy while ensuring contraception.

Profile 2 — Severe hirsutism resistant to combined oral contraceptives

Spironolactone 100–200 mg/day is the first option to consider. In countries where cyproterone acetate is available, doses ≥ 10 mg/day can be discussed for treatment failure, with clear information about the meningioma risk, the shortest possible treatment duration, and neurological surveillance if prolonged use.

Profile 3 — Severe acne requiring contraception (where cyproterone is available)

Diane-35 (cyproterone 2 mg + ethinylestradiol) remains available in several countries for this specific indication. The meningioma risk at the 2 mg dose is not significantly elevated based on available data (Weill 2021). It must not be prescribed solely for contraception. This profile does not apply to US patients where spironolactone remains the only anti-androgen option.

Profile 4 — PCOS without need for contraception (or pregnancy desired in the medium term)

Spironolactone alone (with rigorous barrier contraception) can be considered for hirsutism. It should be discontinued at least 1 month before any conception attempt. Cyproterone acetate is generally not recommended in this context because it suppresses ovulation.

Profile 5 — Documented hyperandrogenism with elevated BMI and insulin resistance

In this mixed profile, anti-androgens alone are insufficient. A combined approach with metformin or GLP-1 agonists (for insulin resistance) and spironolactone (for direct hyperandrogenism) is often more effective than either treatment in isolation. See our metformin vs GLP-1 comparison.

Important safety warnings

Cyproterone acetate ≥ 10 mg/day — EMA/FDA Warning

Meningioma risk × 6.6 at doses ≥ 10 mg/day (JAMA 2021, Weill et al.)
Contraindicated if prior personal meningioma (EMA 2020)
Immediate discontinuation if meningioma diagnosed during treatment
Brain MRI recommended if new neurological symptoms develop during treatment
Use the lowest effective dose for the shortest possible duration
Diane-35 (2 mg): meningioma risk not significantly elevated, but use restricted in many countries
Not available in the United States — US patients should not seek to obtain this drug without FDA-approved supervision

Spironolactone — Precautions

Teratogenic: contraception mandatory — potential feminization of male fetus
Check potassium (basic metabolic panel) at initiation and at 1 month
Monitor blood pressure (hypotensive effect)
Contraindicated in significant renal insufficiency (eGFR < 30 mL/min)
Interactions: ACE inhibitors, ARBs, NSAIDs → additive hyperkalemia risk

Frequently asked questions

Is spironolactone effective for hirsutism in PCOS?: Yes. Doses of 50 to 200 mg/day of spironolactone significantly reduce the Ferriman-Gallwey score after 6 months of treatment. A Cochrane review (Swiglo et al.) and several RCTs in PCOS demonstrate a 30 to 50% reduction in hirsutism score compared to placebo, comparable to cyproterone acetate at equivalent doses. Response is dose-dependent and requires 3 to 6 months for proper assessment.
Is cyproterone acetate available in the United States?: No. Cyproterone acetate is not FDA-approved and is not available in the United States. It remains available in Canada, the UK, Australia, and most European countries. In the US, spironolactone is the most widely used anti-androgen for PCOS-related hirsutism and acne, typically at doses of 50–200 mg/day. Patients in the US should not seek to obtain cyproterone acetate from foreign sources without medical supervision.
What is the actual meningioma risk with cyproterone acetate?: The landmark JAMA 2021 study (Weill et al., Inserm, n = 253,777 women) showed a 6.6-fold increased risk of meningioma in women taking cyproterone acetate at doses ≥ 10 mg/day for more than one year. This risk is dose-dependent and duration-dependent: it is very low at the 2 mg dose (Diane-35) but increases significantly from 10 mg/day (used for severe hirsutism). EMA updated the SmPC in 2020: contraindicated if prior meningioma, and discontinuation recommended if meningioma detected.
Does spironolactone require contraception in PCOS?: Yes, absolutely. Spironolactone is teratogenic — it can feminize the genitals of a male fetus (anti-androgen). Effective contraception is mandatory throughout treatment and for at least one month after stopping. In practice, a combined oral contraceptive pill is often co-prescribed with spironolactone, which also improves control of hirsutism and acne.
Can spironolactone raise potassium levels?: Yes. Spironolactone is an aldosterone antagonist and inhibits renal potassium excretion. A potassium check (basic metabolic panel) is recommended at treatment initiation and after 1 month. In practice, significant hyperkalemia is rare in young women with normal kidney function, but remains a monitoring point — especially if the patient takes other potassium-sparing medications (ACE inhibitors, ARBs, NSAIDs).
How long before spironolactone works for PCOS acne?: Spironolactone acts progressively on hormonal acne. Most patients observe noticeable improvement after 3 to 4 months of treatment. Maximum effect is generally achieved after 6 to 12 months. The usual dose for PCOS acne is 50 to 100 mg/day, with doses up to 200 mg for more resistant cases or hirsutism.
Can spironolactone and cyproterone acetate be taken together?: No, this combination is not recommended. Both molecules are anti-androgens and their combination provides no demonstrated benefit but increases the risk of side effects (hyperkalemia, hypotension, hormonal disruptions). In clinical practice, one or the other is chosen based on the patient's profile and available formulations in their country.
Are there alternatives to anti-androgens for hirsutism in PCOS?: Yes. Alternatives include: (1) combined oral contraceptives (estrogen-progestin pills) that reduce androgen production via gonadotropin suppression; (2) eflornithine cream (Vaniqa) which inhibits facial hair growth locally; (3) laser hair removal or intense pulsed light — non-pharmacological but effective for permanent reduction; (4) finasteride (5 mg) which inhibits 5-alpha-reductase, with less data specific to PCOS.

Sources

How this page was written: See our editorial methodology →