Spironolactone

updated

Spironolactone is an FDA-approved aldosterone antagonist (ALDACTONE, 1960) for heart failure, hypertension, edema and primary hyperaldosteronism, with a 30% lower risk of death in the RALES heart failure trial. Acne has randomized support in women (the 410-woman SAFA trial) and hair loss weaker support in women, and neither describes men: about 9% of male subjects in RALES developed gynecomastia. A PubMed search on 10 October 2026 found no trial of spironolactone for fluid shedding or physique in healthy people, athletes or steroid users.

Aldosterone antagonist

  • FDA first approved ALDACTONE under NDA 012151 on 21 January 1960, and the label has no indication for acne, hirsutism or hair loss.
  • In RALES (1,663 patients with heart failure), spironolactone reduced the risk of death by 30% (95% CI 18% to 40%), and about 9% of male subjects developed gynecomastia.
  • PATHWAY-2 (335 patients with drug-resistant hypertension) found home systolic blood pressure 8.70 mm Hg lower than on placebo.
  • In SAFA (410 women with acne), the Acne-QoL symptom score favored spironolactone at week 12 by 1.27 points (95% CI 0.07 to 2.46).
  • A 48-woman pilot trial in female pattern hair loss did not reach significance on terminal hair count (P = 0.063).
  • In 5 healthy men, spironolactone raised plasma testosterone transiently, and no source found documents a fall in testosterone in men.

What is spironolactone approved to do?

FDA approved ALDACTONE (spironolactone) on 21 January 1960. It is labeled for heart failure, hypertension, edema and primary hyperaldosteronism, and it has no label indication for acne, hirsutism or hair loss.

The ALDACTONE label describes an aldosterone antagonist indicated for NYHA Class III to IV heart failure with reduced ejection fraction, add-on treatment of hypertension, edema in cirrhosis or nephrotic syndrome when other measures fail, and primary hyperaldosteronism. It carries no indication for acne, hirsutism or hair loss. The label version used here took effect on 28 November 2025.

FDA first approved ALDACTONE under NDA 012151 on 21 January 1960. The sponsor on the openFDA record is Pfizer. Approvals outside the United States are not covered here.

Spironolactone is C24H32O4S (416.6 g/mol, CAS 52-01-7, PubChem CID 5833). ALDACTONE and the generics contain spironolactone itself, not a salt, so label doses are spironolactone. Its active metabolites include canrenone.

ALDACTONE label, version effective 28 November 2025: indications, RALES, warnings, PK

FDA prescribing information

DailyMed, U.S. National Library of Medicine. ALDACTONE (spironolactone) film-coated oral tablets, prescribing information, label version effective 28 November 2025. Set ID 0fed2822-3a03-4b64-9857-c682fcd462bc.

The label describes an aldosterone antagonist indicated for NYHA Class III to IV heart failure with reduced ejection fraction, add-on treatment of hypertension, edema in cirrhosis or nephrotic syndrome when other measures fail, and primary hyperaldosteronism. There is no label indication for acne, hirsutism or hair loss. In RALES (1,663 patients with heart failure, 73% male, mean spironolactone dose 26 mg a day), spironolactone reduced the risk of death by 30% (95% CI 18% to 40%), and about 9% of the male subjects developed gynecomastia; the risk rises with dose, onset ranges from 1 to 2 months to over a year, and it is usually reversible. Warnings cover hyperkalemia (with potassium monitoring), hypotension and worsening renal function, electrolyte and metabolic abnormalities, and gynecomastia. The label states spironolactone binds the androgen receptor, that its anti-androgenic properties pose a risk to the male fetus, and that feminization of male fetuses was seen in rats at 200 mg/kg a day. It is a tumorigen in rats in dietary studies, and alopecia is listed among reported adverse reactions. Peak plasma levels of spironolactone and its active metabolite canrenone come at 2.6 and 4.3 hours, food raises bioavailability (AUC) by about 95.4%, and the mean half-life is 1.4 hours for spironolactone and 16.5 hours for canrenone.

Participants / model
Adults with heart failure, hypertension, edema or hyperaldosteronism; RALES participants; rats (animal data)
Treatment
ALDACTONE film-coated oral tablets
Follow-up
Label version effective 28 November 2025
Study design
FDA prescribing information
Funding
not stated in the source

The label's heart failure, gynecomastia and PK figures come from patients and label PK participants. It gives no indication for acne, hirsutism or hair loss, and the rat findings carry no dose or route detail beyond what is stated here.

Read the original source
Drugs@FDA: ALDACTONE approved 21 January 1960

Regulatory record

U.S. Food and Drug Administration. Drugs@FDA application record for NDA 012151 (ALDACTONE). Date read from the openFDA Drugs@FDA record.

FDA first approved ALDACTONE under NDA 012151 on 21 January 1960. The sponsor on the openFDA record is Pfizer.

Participants / model
Not a clinical population
Treatment
Drug application
Follow-up
Approved 1960
Study design
FDA application record
Funding
not stated in the source

This record gives the approval date and sponsor. Indications come from the product label.

Read the original source
PubChem: spironolactone identity

Chemical identity record

National Library of Medicine. PubChem compound record CID 5833 (spironolactone).

Spironolactone: PubChem CID 5833, C24H32O4S, 416.6 g/mol, CAS 52-01-7. ALDACTONE and the generics contain spironolactone itself, not a salt. Its active metabolites include canrenone.

Participants / model
Chemical identity, not a clinical population
Treatment
Defined molecule
Follow-up
Not applicable
Study design
NLM chemical record
Funding
not stated in the source

Identity record only; it says nothing about efficacy or safety.

Read the original source

What did the heart failure and blood pressure trials find?

In RALES, 1,663 patients with heart failure, spironolactone reduced the risk of death by 30%. In PATHWAY-2, 335 patients with drug-resistant hypertension, it lowered home systolic blood pressure by 8.70 mm Hg versus placebo.

In RALES (1,663 patients with heart failure, 73% male, mean spironolactone dose 26 mg a day), spironolactone reduced the risk of death by 30% (95% CI 18% to 40%), as the label summarizes.

PATHWAY-2 randomized 335 patients with drug-resistant hypertension (despite three drugs at maximally tolerated doses) in a double-blind crossover of 12 weeks each on spironolactone 25 to 50 mg, bisoprolol, doxazosin and placebo (NCT02369081). Spironolactone lowered home systolic blood pressure by 8.70 mm Hg versus placebo (95% CI -9.72 to -7.69) and by 4.26 mm Hg more than the average of the other two drugs.

Both populations had heart failure or resistant hypertension. The results do not describe healthy people or men taking spironolactone for physique.

ALDACTONE label, version effective 28 November 2025: indications, RALES, warnings, PK

FDA prescribing information

DailyMed, U.S. National Library of Medicine. ALDACTONE (spironolactone) film-coated oral tablets, prescribing information, label version effective 28 November 2025. Set ID 0fed2822-3a03-4b64-9857-c682fcd462bc.

The label describes an aldosterone antagonist indicated for NYHA Class III to IV heart failure with reduced ejection fraction, add-on treatment of hypertension, edema in cirrhosis or nephrotic syndrome when other measures fail, and primary hyperaldosteronism. There is no label indication for acne, hirsutism or hair loss. In RALES (1,663 patients with heart failure, 73% male, mean spironolactone dose 26 mg a day), spironolactone reduced the risk of death by 30% (95% CI 18% to 40%), and about 9% of the male subjects developed gynecomastia; the risk rises with dose, onset ranges from 1 to 2 months to over a year, and it is usually reversible. Warnings cover hyperkalemia (with potassium monitoring), hypotension and worsening renal function, electrolyte and metabolic abnormalities, and gynecomastia. The label states spironolactone binds the androgen receptor, that its anti-androgenic properties pose a risk to the male fetus, and that feminization of male fetuses was seen in rats at 200 mg/kg a day. It is a tumorigen in rats in dietary studies, and alopecia is listed among reported adverse reactions. Peak plasma levels of spironolactone and its active metabolite canrenone come at 2.6 and 4.3 hours, food raises bioavailability (AUC) by about 95.4%, and the mean half-life is 1.4 hours for spironolactone and 16.5 hours for canrenone.

Participants / model
Adults with heart failure, hypertension, edema or hyperaldosteronism; RALES participants; rats (animal data)
Treatment
ALDACTONE film-coated oral tablets
Follow-up
Label version effective 28 November 2025
Study design
FDA prescribing information
Funding
not stated in the source

The label's heart failure, gynecomastia and PK figures come from patients and label PK participants. It gives no indication for acne, hirsutism or hair loss, and the rat findings carry no dose or route detail beyond what is stated here.

Read the original source
PATHWAY-2: 335 patients with resistant hypertension, home systolic pressure 8.70 mm Hg lower than placebo

Randomized controlled trial

Williams B et al. Lancet. 2015;386(10008):2059-2068. PMID 26414968.

Spironolactone lowered home systolic blood pressure by 8.70 mm Hg versus placebo (95% CI -9.72 to -7.69) and by 4.26 mm Hg more than the average of the other two drugs. Serum potassium exceeded 6.0 mmol/L on one occasion in 6 of 285 patients who received spironolactone.

Participants / model
335 randomized patients with drug-resistant hypertension despite three drugs at maximally tolerated doses
Treatment
Oral spironolactone 25 to 50 mg daily added to baseline drugs, versus bisoprolol, doxazosin and placebo
Follow-up
12 weeks per treatment in a crossover
Study design
Double-blind randomized crossover trial (NCT02369081)
Funding
not stated in the source

Patients with drug-resistant hypertension. The result does not describe healthy people.

Read the original source

Does spironolactone treat acne?

In women, the randomized trials found say yes. In SAFA, 410 women with acne, spironolactone beat placebo on the Acne-QoL symptom score at 12 weeks, and a 5-trial meta-analysis of 563 women found higher objective improvement. Acne is not a labeled use, and no trial in men was found.

SAFA randomized 410 women (mean age 29.2 years) with facial acne of at least 6 months who were judged to warrant oral antibiotics to spironolactone at 50 to 100 mg daily or matched placebo for up to 24 weeks, with 342 in the primary analysis. The primary outcome, Acne-QoL symptom score at week 12, favored spironolactone by 1.27 points (95% CI 0.07 to 2.46), and the gap grew by week 24 (3.45, 95% CI 2.16 to 4.75). Investigator-rated treatment success at week 12 was 19% (31 of 168) versus 6% (9 of 160). Headache was more common on spironolactone (20% versus 12%, P = 0.02), and no serious adverse reactions were reported (ISRCTN12892056).

A 2025 meta-analysis of 5 randomized placebo-controlled trials (563 women with acne, 251 on spironolactone) found objective acne improvement was higher with spironolactone (OR 6.59, 95% CI 3.50 to 12.43, I2 = 0%), while subjective assessment did not differ (OR 5.22, 95% CI 0.62 to 44.24, I2 = 85%). Menstrual irregularities (OR 1.09, 95% CI 0.37 to 3.25) and breast enlargement (OR 1.37, 95% CI 0.79 to 2.38) were not significantly different from placebo.

All of this is evidence in women. The doses in these trials come from women's trials and should not be read across to men, and no trial in men with acne was found.

SAFA: 410 women with acne, Acne-QoL symptom score better by 1.27 points at week 12

Randomized controlled trial

Santer M et al. BMJ. 2023;381:e074349. PMID 37192767.

The primary outcome, Acne-QoL symptom score at week 12, favored spironolactone by 1.27 points (95% CI 0.07 to 2.46), and the gap grew by week 24 (3.45, 95% CI 2.16 to 4.75). Investigator-rated treatment success at week 12 was 19% (31 of 168) versus 6% (9 of 160). Headache was more common on spironolactone (20% versus 12%, P = 0.02), and no serious adverse reactions were reported.

Participants / model
410 randomized women (mean age 29.2 years) with facial acne of at least 6 months who were judged to warrant oral antibiotics; 342 in the primary analysis
Treatment
Oral spironolactone at 50 to 100 mg daily, or matched placebo
Follow-up
Up to 24 weeks
Study design
Randomized placebo-controlled trial (ISRCTN12892056)
Funding
not stated in the source

Women only. Endpoints were Acne-QoL symptom score, self-assessed improvement, investigator global assessment and adverse reactions.

Read the original source
Acne meta-analysis: 5 trials, 563 women, objective improvement OR 6.59

Systematic review and meta-analysis

Ghanem L et al. J Cosmet Dermatol. 2025;24(8):e70411. PMID 40823723.

Objective acne improvement was higher with spironolactone (OR 6.59, 95% CI 3.50 to 12.43, I2 = 0%), while subjective assessment did not differ (OR 5.22, 95% CI 0.62 to 44.24, I2 = 85%). Menstrual irregularities (OR 1.09, 95% CI 0.37 to 3.25) and breast enlargement (OR 1.37, 95% CI 0.79 to 2.38) were not significantly different from placebo.

Participants / model
563 women with acne across 5 randomized trials, 251 of them on spironolactone
Treatment
Oral spironolactone versus placebo
Follow-up
Pooled randomized trials
Study design
2025 systematic review and meta-analysis of 5 randomized placebo-controlled trials
Funding
not stated in the source

Five trials, women only.

Read the original source

Does spironolactone treat hair loss?

Weakly, and only in women. The Cochrane review of female pattern hair loss supplies no pooled spironolactone result, a 48-woman pilot trial missed significance on terminal hair count, and a mixed-design meta-analysis reports improvement rates that are not placebo-controlled. No trial in men was found.

The 2016 Cochrane review of interventions for female pattern hair loss searched to July 2015 and included 47 randomized trials with 5,290 participants, only five at low risk of bias. It found moderate-quality evidence for topical minoxidil, found finasteride 1 mg no better than placebo (low-quality evidence), and listed spironolactone among treatments for which further randomized trials were needed. It supplies no pooled spironolactone efficacy result.

A 2025 randomized double-blind placebo-controlled pilot trial gave 48 premenopausal women aged 21 to 45 with mild-to-moderate female pattern hair loss spironolactone 100 mg or placebo for 24 weeks, with minoxidil 3% solution in both arms. Terminal hair count rose 9.48 versus 5.32 hairs per cm2 (P = 0.063, not significant), hair diameter rose 4.23 versus 2.96 micrometers, and moderate-to-marked global improvement was 38% versus 9% (P = 0.034). Menstrual irregularities occurred in 37.5% on spironolactone. The authors flag the small sample.

A 2023 systematic review and meta-analysis of randomized and observational studies of oral spironolactone in female pattern hair loss reported an overall improvement rate of 56.60% (65.80% with combined therapy versus 43.21% as monotherapy), with significant heterogeneity, and no improvement or only modest improvement in 37.80% of patients. These pooled rates mix study designs and are not placebo-controlled effects.

Certainty is low for hair loss in women, and no trial of male pattern hair loss or hair loss in men was found.

Cochrane review: 47 trials, 5,290 participants, no pooled spironolactone result

Systematic review and meta-analysis

van Zuuren EJ et al. Cochrane Database Syst Rev. 2016;2016(5):CD007628. PMID 27225981.

The review found moderate-quality evidence for topical minoxidil, found finasteride 1 mg no better than placebo (low-quality evidence), and listed spironolactone among treatments for which further randomized trials were needed. It supplies no pooled spironolactone efficacy result. Only five of the 47 trials were at low risk of bias.

Participants / model
5,290 participants in 47 randomized trials, women with female pattern hair loss
Treatment
Mostly topical minoxidil; other interventions
Follow-up
Searched to July 2015
Study design
Cochrane systematic review (2016)
Funding
not stated in the source

It does not say spironolactone works or fails; it says more trials were needed.

Read the original source
Pilot: 48 premenopausal women, terminal hair count not significant (P = 0.063)

Randomized controlled trial

Werachattawatchai P et al. Int J Womens Dermatol. 2025;11(3):e227. PMID 40978669.

Terminal hair count rose 9.48 versus 5.32 hairs per cm2 (P = 0.063, not significant), hair diameter rose 4.23 versus 2.96 micrometers, and moderate-to-marked global improvement was 38% versus 9% (P = 0.034). Menstrual irregularities occurred in 37.5% on spironolactone. The authors flag the small sample.

Participants / model
48 premenopausal women aged 21 to 45 with mild-to-moderate female pattern hair loss
Treatment
Oral spironolactone 100 mg daily plus topical minoxidil 3% solution, or placebo plus minoxidil
Follow-up
24 weeks
Study design
2025 randomized double-blind placebo-controlled pilot trial
Funding
not stated in the source

Minoxidil was given in both arms. Endpoints were terminal hair count, hair diameter, global photographic assessment and adverse events.

Read the original source
Mixed-design meta-analysis: overall improvement rate 56.60%

Systematic review and meta-analysis

Aleissa M. Cureus. 2023;15(8):e43559. PMID 37719557.

The overall improvement rate was 56.60% (65.80% with combined therapy versus 43.21% as monotherapy), with significant heterogeneity, and 37.80% of patients had no improvement or only modest improvement. Reported adverse events included scalp pruritus or increased scurf (18.92%), menstrual disorders (11.85%) and facial hypertrichosis (6.93%).

Participants / model
Women with female pattern hair loss across mixed randomized and observational studies
Treatment
Oral spironolactone, alone or with other treatments
Follow-up
Pooled studies
Study design
2023 systematic review and meta-analysis of randomized and observational studies
Funding
not stated in the source

Pooled rates mix study designs and are not placebo-controlled effects.

Read the original source

What is known about spironolactone in men?

Little supports use in men. The label reports gynecomastia in about 9% of male subjects in RALES, a review names spironolactone as definitely associated with gynecomastia, and the one small hormone study found a transient rise in testosterone in 5 healthy men, not a fall.

The label reports that about 9% of the male subjects in RALES developed gynecomastia. The risk rises with dose, onset ranges from 1 to 2 months to over a year, and it is usually reversible.

An evidence-based review of drug-induced gynecomastia (Medline, EMBASE and BIOSIS searched from 1940) rated the evidence for most drug associations as poor, and named spironolactone among the drugs definitely associated with gynecomastia, with anabolic steroids among those probably associated.

In a double-blind controlled study of 5 healthy male volunteers, spironolactone 200 mg daily changed the pattern of plasma testosterone and LH versus placebo and raised urinary androsterone, etiocholanolone and total estrogen excretion. The authors concluded that treatment for 2 to 4 days leads to a transient rise in plasma testosterone, that continued treatment (4 to 10 days) raises LH secretion with normalized testosterone, and that androgen-to-estrogen conversion rises slightly. This 1978 study in 5 men at a high dose is not evidence of an androgen-lowering effect in healthy men.

ALDACTONE label, version effective 28 November 2025: indications, RALES, warnings, PK

FDA prescribing information

DailyMed, U.S. National Library of Medicine. ALDACTONE (spironolactone) film-coated oral tablets, prescribing information, label version effective 28 November 2025. Set ID 0fed2822-3a03-4b64-9857-c682fcd462bc.

The label describes an aldosterone antagonist indicated for NYHA Class III to IV heart failure with reduced ejection fraction, add-on treatment of hypertension, edema in cirrhosis or nephrotic syndrome when other measures fail, and primary hyperaldosteronism. There is no label indication for acne, hirsutism or hair loss. In RALES (1,663 patients with heart failure, 73% male, mean spironolactone dose 26 mg a day), spironolactone reduced the risk of death by 30% (95% CI 18% to 40%), and about 9% of the male subjects developed gynecomastia; the risk rises with dose, onset ranges from 1 to 2 months to over a year, and it is usually reversible. Warnings cover hyperkalemia (with potassium monitoring), hypotension and worsening renal function, electrolyte and metabolic abnormalities, and gynecomastia. The label states spironolactone binds the androgen receptor, that its anti-androgenic properties pose a risk to the male fetus, and that feminization of male fetuses was seen in rats at 200 mg/kg a day. It is a tumorigen in rats in dietary studies, and alopecia is listed among reported adverse reactions. Peak plasma levels of spironolactone and its active metabolite canrenone come at 2.6 and 4.3 hours, food raises bioavailability (AUC) by about 95.4%, and the mean half-life is 1.4 hours for spironolactone and 16.5 hours for canrenone.

Participants / model
Adults with heart failure, hypertension, edema or hyperaldosteronism; RALES participants; rats (animal data)
Treatment
ALDACTONE film-coated oral tablets
Follow-up
Label version effective 28 November 2025
Study design
FDA prescribing information
Funding
not stated in the source

The label's heart failure, gynecomastia and PK figures come from patients and label PK participants. It gives no indication for acne, hirsutism or hair loss, and the rat findings carry no dose or route detail beyond what is stated here.

Read the original source
Evidence-based review: spironolactone definitely associated with gynecomastia

Human study

Deepinder F et al. Expert Opin Drug Saf. 2012;11(5):779-95. PMID 22862307.

The review rated the evidence for most drug associations as poor. It named spironolactone among the drugs definitely associated with gynecomastia, with anabolic steroids among those probably associated.

Participants / model
Men with drug-induced gynecomastia (review of case reports and series)
Treatment
Not drug-specific
Follow-up
Medline, EMBASE and BIOSIS searched from 1940
Study design
Evidence-based review
Funding
not stated in the source

A review of associations, not a trial.

Read the original source
1978 study: 5 healthy men, transient testosterone rise

Human study

Tidd MJ et al. Clin Endocrinol (Oxf). 1978;9(5):389-99. PMID 152681.

Spironolactone 200 mg daily changed the pattern of plasma testosterone and LH versus placebo and raised urinary androsterone, etiocholanolone and total estrogen excretion. The authors concluded that treatment for 2 to 4 days leads to a transient rise in plasma testosterone, that continued treatment (4 to 10 days) raises LH secretion with normalized testosterone, and that androgen-to-estrogen conversion rises slightly.

Participants / model
5 healthy male volunteers
Treatment
Oral spironolactone 200 mg daily for several days, versus placebo
Follow-up
Several days
Study design
Double-blind controlled study (1978)
Funding
not stated in the source

A hormone study in 5 men at a high dose. It is not evidence of an androgen-lowering effect in healthy men.

Read the original source

Does spironolactone shed water or lower androgens in healthy people and athletes?

No trial found tests it. A PubMed search on 10 October 2026 returned 22 records on spironolactone with bodybuilding, doping, athlete or anabolic terms, and none tested fluid shedding or physique in healthy people, athletes or steroid users.

Sellers describe spironolactone as a drug for fluid retention, blood pressure, acne and hair loss that works through anti-androgen and diuretic effects. Blood pressure and edema are labeled uses, and the acne and hair loss results above come from women and do not transfer to men.

A PubMed search on 10 October 2026 for spironolactone with bodybuilding, doping, athlete or anabolic terms returned 22 records: diuretic-detection methods for doping control, rodent studies, drug-induced gynecomastia reviews, historical papers and heart failure papers. None tested spironolactone for fluid shedding or physique in healthy people, athletes or steroid users.

A second search for spironolactone with water or fluid retention in healthy people, athletes or men returned 5 records: reviews of resistant hypertension and cirrhotic ascites, and one randomized trial in 54 men with severe sleep apnea (DESALT, PMID 29669139, NCT01945801) in which spironolactone plus furosemide for 1 week lowered total body water by 2.2 L. That trial combined two diuretics in sleep apnea patients, so it does not test spironolactone alone in healthy people. Cosmetic or contest fluid-shedding use has no trial behind it among these records.

The anti-androgen claim is addressed under mechanism: the label describes receptor binding, and no source found documents a testosterone fall in men.

PubMed searches, 10 October 2026: 22 records and 5 records, none testing fluid shedding or physique

PubMed search record

PubMed searches run on 10 October 2026: (1) spironolactone[tiab] AND (bodybuilder*[tiab] OR bodybuilding[tiab] OR doping[tiab] OR athlete*[tiab] OR anabolic[tiab]); (2) spironolactone[tiab] AND ("water retention"[tiab] OR "fluid retention"[tiab]) AND (healthy[tiab] OR athlete*[tiab] OR men[tiab]). 22 and 5 records returned.

The first search returned 22 records: diuretic-detection methods for doping control, rodent studies, drug-induced gynecomastia reviews, historical papers and heart failure papers. None tested spironolactone for fluid shedding or physique in healthy people, athletes or steroid users. The second search returned 5 records: reviews of resistant hypertension and cirrhotic ascites, and one randomized trial in 54 men with severe sleep apnea (DESALT, PMID 29669139, NCT01945801) in which spironolactone plus furosemide for 1 week lowered total body water by 2.2 L. That trial combined two diuretics in sleep apnea patients, so it does not test spironolactone alone in healthy people.

Participants / model
Records returned, not a population
Treatment
Not applicable
Follow-up
Searches run on 10 October 2026
Study design
Literature search
Funding
not stated in the source

A search result shows what PubMed returned on that date. It is not proof that no unindexed study exists.

Read the original source
ALDACTONE label, version effective 28 November 2025: indications, RALES, warnings, PK

FDA prescribing information

DailyMed, U.S. National Library of Medicine. ALDACTONE (spironolactone) film-coated oral tablets, prescribing information, label version effective 28 November 2025. Set ID 0fed2822-3a03-4b64-9857-c682fcd462bc.

The label describes an aldosterone antagonist indicated for NYHA Class III to IV heart failure with reduced ejection fraction, add-on treatment of hypertension, edema in cirrhosis or nephrotic syndrome when other measures fail, and primary hyperaldosteronism. There is no label indication for acne, hirsutism or hair loss. In RALES (1,663 patients with heart failure, 73% male, mean spironolactone dose 26 mg a day), spironolactone reduced the risk of death by 30% (95% CI 18% to 40%), and about 9% of the male subjects developed gynecomastia; the risk rises with dose, onset ranges from 1 to 2 months to over a year, and it is usually reversible. Warnings cover hyperkalemia (with potassium monitoring), hypotension and worsening renal function, electrolyte and metabolic abnormalities, and gynecomastia. The label states spironolactone binds the androgen receptor, that its anti-androgenic properties pose a risk to the male fetus, and that feminization of male fetuses was seen in rats at 200 mg/kg a day. It is a tumorigen in rats in dietary studies, and alopecia is listed among reported adverse reactions. Peak plasma levels of spironolactone and its active metabolite canrenone come at 2.6 and 4.3 hours, food raises bioavailability (AUC) by about 95.4%, and the mean half-life is 1.4 hours for spironolactone and 16.5 hours for canrenone.

Participants / model
Adults with heart failure, hypertension, edema or hyperaldosteronism; RALES participants; rats (animal data)
Treatment
ALDACTONE film-coated oral tablets
Follow-up
Label version effective 28 November 2025
Study design
FDA prescribing information
Funding
not stated in the source

The label's heart failure, gynecomastia and PK figures come from patients and label PK participants. It gives no indication for acne, hirsutism or hair loss, and the rat findings carry no dose or route detail beyond what is stated here.

Read the original source
1978 study: 5 healthy men, transient testosterone rise

Human study

Tidd MJ et al. Clin Endocrinol (Oxf). 1978;9(5):389-99. PMID 152681.

Spironolactone 200 mg daily changed the pattern of plasma testosterone and LH versus placebo and raised urinary androsterone, etiocholanolone and total estrogen excretion. The authors concluded that treatment for 2 to 4 days leads to a transient rise in plasma testosterone, that continued treatment (4 to 10 days) raises LH secretion with normalized testosterone, and that androgen-to-estrogen conversion rises slightly.

Participants / model
5 healthy male volunteers
Treatment
Oral spironolactone 200 mg daily for several days, versus placebo
Follow-up
Several days
Study design
Double-blind controlled study (1978)
Funding
not stated in the source

A hormone study in 5 men at a high dose. It is not evidence of an androgen-lowering effect in healthy men.

Read the original source

How does spironolactone work, and what does the body do with it?

Spironolactone is an aldosterone antagonist, and the label states it binds the androgen receptor. No source found documents a fall in testosterone in men. Peak plasma levels of spironolactone and its active metabolite canrenone come at 2.6 and 4.3 hours, and mean half-lives are 1.4 and 16.5 hours.

The label describes spironolactone as an aldosterone antagonist and states that it binds the androgen receptor. The anti-androgen effect described for it is receptor antagonism per the label, not a documented fall in testosterone in men.

The one small human hormone study found a transient rise in plasma testosterone in 5 healthy men, followed by higher LH with normalized testosterone, so this page makes no claim that spironolactone lowers androgens.

In the label, peak plasma levels of spironolactone and its active metabolite canrenone come at 2.6 and 4.3 hours. Food raises bioavailability (AUC) by about 95.4%, and the mean half-life is 1.4 hours for spironolactone and 16.5 hours for canrenone.

ALDACTONE label, version effective 28 November 2025: indications, RALES, warnings, PK

FDA prescribing information

DailyMed, U.S. National Library of Medicine. ALDACTONE (spironolactone) film-coated oral tablets, prescribing information, label version effective 28 November 2025. Set ID 0fed2822-3a03-4b64-9857-c682fcd462bc.

The label describes an aldosterone antagonist indicated for NYHA Class III to IV heart failure with reduced ejection fraction, add-on treatment of hypertension, edema in cirrhosis or nephrotic syndrome when other measures fail, and primary hyperaldosteronism. There is no label indication for acne, hirsutism or hair loss. In RALES (1,663 patients with heart failure, 73% male, mean spironolactone dose 26 mg a day), spironolactone reduced the risk of death by 30% (95% CI 18% to 40%), and about 9% of the male subjects developed gynecomastia; the risk rises with dose, onset ranges from 1 to 2 months to over a year, and it is usually reversible. Warnings cover hyperkalemia (with potassium monitoring), hypotension and worsening renal function, electrolyte and metabolic abnormalities, and gynecomastia. The label states spironolactone binds the androgen receptor, that its anti-androgenic properties pose a risk to the male fetus, and that feminization of male fetuses was seen in rats at 200 mg/kg a day. It is a tumorigen in rats in dietary studies, and alopecia is listed among reported adverse reactions. Peak plasma levels of spironolactone and its active metabolite canrenone come at 2.6 and 4.3 hours, food raises bioavailability (AUC) by about 95.4%, and the mean half-life is 1.4 hours for spironolactone and 16.5 hours for canrenone.

Participants / model
Adults with heart failure, hypertension, edema or hyperaldosteronism; RALES participants; rats (animal data)
Treatment
ALDACTONE film-coated oral tablets
Follow-up
Label version effective 28 November 2025
Study design
FDA prescribing information
Funding
not stated in the source

The label's heart failure, gynecomastia and PK figures come from patients and label PK participants. It gives no indication for acne, hirsutism or hair loss, and the rat findings carry no dose or route detail beyond what is stated here.

Read the original source
1978 study: 5 healthy men, transient testosterone rise

Human study

Tidd MJ et al. Clin Endocrinol (Oxf). 1978;9(5):389-99. PMID 152681.

Spironolactone 200 mg daily changed the pattern of plasma testosterone and LH versus placebo and raised urinary androsterone, etiocholanolone and total estrogen excretion. The authors concluded that treatment for 2 to 4 days leads to a transient rise in plasma testosterone, that continued treatment (4 to 10 days) raises LH secretion with normalized testosterone, and that androgen-to-estrogen conversion rises slightly.

Participants / model
5 healthy male volunteers
Treatment
Oral spironolactone 200 mg daily for several days, versus placebo
Follow-up
Several days
Study design
Double-blind controlled study (1978)
Funding
not stated in the source

A hormone study in 5 men at a high dose. It is not evidence of an androgen-lowering effect in healthy men.

Read the original source

What risks do the label and the studies report?

The label warns of hyperkalemia, hypotension and worsening renal function, electrolyte and metabolic abnormalities, gynecomastia (about 9% of men in RALES) and a risk to the male fetus, and it is a tumorigen in rats in dietary studies. In trials, potassium above 6.0 mmol/L occurred in 6 of 285 patients with resistant hypertension, and no men with acne or hair loss were studied.

The ALDACTONE label warns of hyperkalemia (with potassium monitoring), hypotension and worsening renal function, electrolyte and metabolic abnormalities, and gynecomastia. It states that spironolactone binds the androgen receptor, that its anti-androgenic properties pose a risk to the male fetus, and that feminization of male fetuses was seen in rats at 200 mg/kg a day. The label describes spironolactone as a tumorigen in rats in dietary studies, and lists alopecia among reported adverse reactions. No human cancer study is cited here.

In PATHWAY-2, serum potassium exceeded 6.0 mmol/L on one occasion in 6 of 285 patients who received spironolactone. In SAFA, headache was more common on spironolactone (20% versus 12%, P = 0.02) and no serious adverse reactions were reported. In the 48-woman hair loss pilot trial, menstrual irregularities occurred in 37.5% on spironolactone, and the mixed-design hair loss meta-analysis reported scalp pruritus or increased scurf (18.92%), menstrual disorders (11.85%) and facial hypertrichosis (6.93%).

In 974 healthy young women taking spironolactone for acne at 2 US tertiary care centers, 13 abnormal potassium results in 1,802 measurements gave a hyperkalemia rate of 0.72%, against a 0.76% baseline rate in a comparison group of 1,165 healthy young women, and 6 of the 13 repeat tests were normal. The authors concluded that routine potassium monitoring is unnecessary for healthy women taking spironolactone for acne. People with cardiovascular disease, renal failure or renin-angiotensin drugs were excluded and no men were studied, so this applies to that population only.

ALDACTONE label, version effective 28 November 2025: indications, RALES, warnings, PK

FDA prescribing information

DailyMed, U.S. National Library of Medicine. ALDACTONE (spironolactone) film-coated oral tablets, prescribing information, label version effective 28 November 2025. Set ID 0fed2822-3a03-4b64-9857-c682fcd462bc.

The label describes an aldosterone antagonist indicated for NYHA Class III to IV heart failure with reduced ejection fraction, add-on treatment of hypertension, edema in cirrhosis or nephrotic syndrome when other measures fail, and primary hyperaldosteronism. There is no label indication for acne, hirsutism or hair loss. In RALES (1,663 patients with heart failure, 73% male, mean spironolactone dose 26 mg a day), spironolactone reduced the risk of death by 30% (95% CI 18% to 40%), and about 9% of the male subjects developed gynecomastia; the risk rises with dose, onset ranges from 1 to 2 months to over a year, and it is usually reversible. Warnings cover hyperkalemia (with potassium monitoring), hypotension and worsening renal function, electrolyte and metabolic abnormalities, and gynecomastia. The label states spironolactone binds the androgen receptor, that its anti-androgenic properties pose a risk to the male fetus, and that feminization of male fetuses was seen in rats at 200 mg/kg a day. It is a tumorigen in rats in dietary studies, and alopecia is listed among reported adverse reactions. Peak plasma levels of spironolactone and its active metabolite canrenone come at 2.6 and 4.3 hours, food raises bioavailability (AUC) by about 95.4%, and the mean half-life is 1.4 hours for spironolactone and 16.5 hours for canrenone.

Participants / model
Adults with heart failure, hypertension, edema or hyperaldosteronism; RALES participants; rats (animal data)
Treatment
ALDACTONE film-coated oral tablets
Follow-up
Label version effective 28 November 2025
Study design
FDA prescribing information
Funding
not stated in the source

The label's heart failure, gynecomastia and PK figures come from patients and label PK participants. It gives no indication for acne, hirsutism or hair loss, and the rat findings carry no dose or route detail beyond what is stated here.

Read the original source
PATHWAY-2: 335 patients with resistant hypertension, home systolic pressure 8.70 mm Hg lower than placebo

Randomized controlled trial

Williams B et al. Lancet. 2015;386(10008):2059-2068. PMID 26414968.

Spironolactone lowered home systolic blood pressure by 8.70 mm Hg versus placebo (95% CI -9.72 to -7.69) and by 4.26 mm Hg more than the average of the other two drugs. Serum potassium exceeded 6.0 mmol/L on one occasion in 6 of 285 patients who received spironolactone.

Participants / model
335 randomized patients with drug-resistant hypertension despite three drugs at maximally tolerated doses
Treatment
Oral spironolactone 25 to 50 mg daily added to baseline drugs, versus bisoprolol, doxazosin and placebo
Follow-up
12 weeks per treatment in a crossover
Study design
Double-blind randomized crossover trial (NCT02369081)
Funding
not stated in the source

Patients with drug-resistant hypertension. The result does not describe healthy people.

Read the original source
SAFA: 410 women with acne, Acne-QoL symptom score better by 1.27 points at week 12

Randomized controlled trial

Santer M et al. BMJ. 2023;381:e074349. PMID 37192767.

The primary outcome, Acne-QoL symptom score at week 12, favored spironolactone by 1.27 points (95% CI 0.07 to 2.46), and the gap grew by week 24 (3.45, 95% CI 2.16 to 4.75). Investigator-rated treatment success at week 12 was 19% (31 of 168) versus 6% (9 of 160). Headache was more common on spironolactone (20% versus 12%, P = 0.02), and no serious adverse reactions were reported.

Participants / model
410 randomized women (mean age 29.2 years) with facial acne of at least 6 months who were judged to warrant oral antibiotics; 342 in the primary analysis
Treatment
Oral spironolactone at 50 to 100 mg daily, or matched placebo
Follow-up
Up to 24 weeks
Study design
Randomized placebo-controlled trial (ISRCTN12892056)
Funding
not stated in the source

Women only. Endpoints were Acne-QoL symptom score, self-assessed improvement, investigator global assessment and adverse reactions.

Read the original source
Pilot: 48 premenopausal women, terminal hair count not significant (P = 0.063)

Randomized controlled trial

Werachattawatchai P et al. Int J Womens Dermatol. 2025;11(3):e227. PMID 40978669.

Terminal hair count rose 9.48 versus 5.32 hairs per cm2 (P = 0.063, not significant), hair diameter rose 4.23 versus 2.96 micrometers, and moderate-to-marked global improvement was 38% versus 9% (P = 0.034). Menstrual irregularities occurred in 37.5% on spironolactone. The authors flag the small sample.

Participants / model
48 premenopausal women aged 21 to 45 with mild-to-moderate female pattern hair loss
Treatment
Oral spironolactone 100 mg daily plus topical minoxidil 3% solution, or placebo plus minoxidil
Follow-up
24 weeks
Study design
2025 randomized double-blind placebo-controlled pilot trial
Funding
not stated in the source

Minoxidil was given in both arms. Endpoints were terminal hair count, hair diameter, global photographic assessment and adverse events.

Read the original source
Mixed-design meta-analysis: overall improvement rate 56.60%

Systematic review and meta-analysis

Aleissa M. Cureus. 2023;15(8):e43559. PMID 37719557.

The overall improvement rate was 56.60% (65.80% with combined therapy versus 43.21% as monotherapy), with significant heterogeneity, and 37.80% of patients had no improvement or only modest improvement. Reported adverse events included scalp pruritus or increased scurf (18.92%), menstrual disorders (11.85%) and facial hypertrichosis (6.93%).

Participants / model
Women with female pattern hair loss across mixed randomized and observational studies
Treatment
Oral spironolactone, alone or with other treatments
Follow-up
Pooled studies
Study design
2023 systematic review and meta-analysis of randomized and observational studies
Funding
not stated in the source

Pooled rates mix study designs and are not placebo-controlled effects.

Read the original source
974 women on spironolactone for acne: hyperkalemia rate 0.72% versus 0.76% baseline

Human study

Plovanich M et al. JAMA Dermatol. 2015;151(9):941-4. PMID 25796182.

There were 13 abnormal potassium results in 1,802 measurements, a hyperkalemia rate of 0.72%, against a 0.76% baseline rate in a comparison group of 1,165 healthy young women (taking and not taking spironolactone); 6 of the 13 repeat tests were normal. The authors concluded that routine potassium monitoring is unnecessary for healthy women taking spironolactone for acne.

Participants / model
974 healthy young women taking spironolactone for acne at 2 US tertiary care centers; 1,165 women for the baseline rate
Treatment
Oral spironolactone; doses not stated in the abstract
Follow-up
not stated in the source
Study design
Retrospective cohort
Funding
not stated in the source

Cardiovascular disease, renal failure and renin-angiotensin drugs were exclusions, and no men were studied. The conclusion applies to that population only.

Read the original source

Why does spironolactone sit in A tier?

The A rests on an FDA approval since 1960, a mortality benefit in heart failure and the best blood pressure result in resistant hypertension. Acne has randomized support in women and hair loss weaker support in women, and nothing found supports use in men or fluid shedding in healthy people.

The A applies to the approved uses and, for acne, to women. Blood pressure and edema are labeled uses with trial support, acne is supported in women by the 410-woman SAFA trial and a 5-trial meta-analysis, and hair loss is weakly supported in women by one 48-woman pilot trial that missed significance on its main count, a mixed-design meta-analysis and a Cochrane review that called for trials.

None of that describes men. The label's gynecomastia rate (about 9% of male subjects in RALES) and the review naming spironolactone as definitely associated with gynecomastia cut against its use as an anti-androgen in men, and the search run on 10 October 2026 found no trial of fluid shedding in healthy people.

ALDACTONE label, version effective 28 November 2025: indications, RALES, warnings, PK

FDA prescribing information

DailyMed, U.S. National Library of Medicine. ALDACTONE (spironolactone) film-coated oral tablets, prescribing information, label version effective 28 November 2025. Set ID 0fed2822-3a03-4b64-9857-c682fcd462bc.

The label describes an aldosterone antagonist indicated for NYHA Class III to IV heart failure with reduced ejection fraction, add-on treatment of hypertension, edema in cirrhosis or nephrotic syndrome when other measures fail, and primary hyperaldosteronism. There is no label indication for acne, hirsutism or hair loss. In RALES (1,663 patients with heart failure, 73% male, mean spironolactone dose 26 mg a day), spironolactone reduced the risk of death by 30% (95% CI 18% to 40%), and about 9% of the male subjects developed gynecomastia; the risk rises with dose, onset ranges from 1 to 2 months to over a year, and it is usually reversible. Warnings cover hyperkalemia (with potassium monitoring), hypotension and worsening renal function, electrolyte and metabolic abnormalities, and gynecomastia. The label states spironolactone binds the androgen receptor, that its anti-androgenic properties pose a risk to the male fetus, and that feminization of male fetuses was seen in rats at 200 mg/kg a day. It is a tumorigen in rats in dietary studies, and alopecia is listed among reported adverse reactions. Peak plasma levels of spironolactone and its active metabolite canrenone come at 2.6 and 4.3 hours, food raises bioavailability (AUC) by about 95.4%, and the mean half-life is 1.4 hours for spironolactone and 16.5 hours for canrenone.

Participants / model
Adults with heart failure, hypertension, edema or hyperaldosteronism; RALES participants; rats (animal data)
Treatment
ALDACTONE film-coated oral tablets
Follow-up
Label version effective 28 November 2025
Study design
FDA prescribing information
Funding
not stated in the source

The label's heart failure, gynecomastia and PK figures come from patients and label PK participants. It gives no indication for acne, hirsutism or hair loss, and the rat findings carry no dose or route detail beyond what is stated here.

Read the original source
Drugs@FDA: ALDACTONE approved 21 January 1960

Regulatory record

U.S. Food and Drug Administration. Drugs@FDA application record for NDA 012151 (ALDACTONE). Date read from the openFDA Drugs@FDA record.

FDA first approved ALDACTONE under NDA 012151 on 21 January 1960. The sponsor on the openFDA record is Pfizer.

Participants / model
Not a clinical population
Treatment
Drug application
Follow-up
Approved 1960
Study design
FDA application record
Funding
not stated in the source

This record gives the approval date and sponsor. Indications come from the product label.

Read the original source
PATHWAY-2: 335 patients with resistant hypertension, home systolic pressure 8.70 mm Hg lower than placebo

Randomized controlled trial

Williams B et al. Lancet. 2015;386(10008):2059-2068. PMID 26414968.

Spironolactone lowered home systolic blood pressure by 8.70 mm Hg versus placebo (95% CI -9.72 to -7.69) and by 4.26 mm Hg more than the average of the other two drugs. Serum potassium exceeded 6.0 mmol/L on one occasion in 6 of 285 patients who received spironolactone.

Participants / model
335 randomized patients with drug-resistant hypertension despite three drugs at maximally tolerated doses
Treatment
Oral spironolactone 25 to 50 mg daily added to baseline drugs, versus bisoprolol, doxazosin and placebo
Follow-up
12 weeks per treatment in a crossover
Study design
Double-blind randomized crossover trial (NCT02369081)
Funding
not stated in the source

Patients with drug-resistant hypertension. The result does not describe healthy people.

Read the original source
SAFA: 410 women with acne, Acne-QoL symptom score better by 1.27 points at week 12

Randomized controlled trial

Santer M et al. BMJ. 2023;381:e074349. PMID 37192767.

The primary outcome, Acne-QoL symptom score at week 12, favored spironolactone by 1.27 points (95% CI 0.07 to 2.46), and the gap grew by week 24 (3.45, 95% CI 2.16 to 4.75). Investigator-rated treatment success at week 12 was 19% (31 of 168) versus 6% (9 of 160). Headache was more common on spironolactone (20% versus 12%, P = 0.02), and no serious adverse reactions were reported.

Participants / model
410 randomized women (mean age 29.2 years) with facial acne of at least 6 months who were judged to warrant oral antibiotics; 342 in the primary analysis
Treatment
Oral spironolactone at 50 to 100 mg daily, or matched placebo
Follow-up
Up to 24 weeks
Study design
Randomized placebo-controlled trial (ISRCTN12892056)
Funding
not stated in the source

Women only. Endpoints were Acne-QoL symptom score, self-assessed improvement, investigator global assessment and adverse reactions.

Read the original source
Acne meta-analysis: 5 trials, 563 women, objective improvement OR 6.59

Systematic review and meta-analysis

Ghanem L et al. J Cosmet Dermatol. 2025;24(8):e70411. PMID 40823723.

Objective acne improvement was higher with spironolactone (OR 6.59, 95% CI 3.50 to 12.43, I2 = 0%), while subjective assessment did not differ (OR 5.22, 95% CI 0.62 to 44.24, I2 = 85%). Menstrual irregularities (OR 1.09, 95% CI 0.37 to 3.25) and breast enlargement (OR 1.37, 95% CI 0.79 to 2.38) were not significantly different from placebo.

Participants / model
563 women with acne across 5 randomized trials, 251 of them on spironolactone
Treatment
Oral spironolactone versus placebo
Follow-up
Pooled randomized trials
Study design
2025 systematic review and meta-analysis of 5 randomized placebo-controlled trials
Funding
not stated in the source

Five trials, women only.

Read the original source
Pilot: 48 premenopausal women, terminal hair count not significant (P = 0.063)

Randomized controlled trial

Werachattawatchai P et al. Int J Womens Dermatol. 2025;11(3):e227. PMID 40978669.

Terminal hair count rose 9.48 versus 5.32 hairs per cm2 (P = 0.063, not significant), hair diameter rose 4.23 versus 2.96 micrometers, and moderate-to-marked global improvement was 38% versus 9% (P = 0.034). Menstrual irregularities occurred in 37.5% on spironolactone. The authors flag the small sample.

Participants / model
48 premenopausal women aged 21 to 45 with mild-to-moderate female pattern hair loss
Treatment
Oral spironolactone 100 mg daily plus topical minoxidil 3% solution, or placebo plus minoxidil
Follow-up
24 weeks
Study design
2025 randomized double-blind placebo-controlled pilot trial
Funding
not stated in the source

Minoxidil was given in both arms. Endpoints were terminal hair count, hair diameter, global photographic assessment and adverse events.

Read the original source
Cochrane review: 47 trials, 5,290 participants, no pooled spironolactone result

Systematic review and meta-analysis

van Zuuren EJ et al. Cochrane Database Syst Rev. 2016;2016(5):CD007628. PMID 27225981.

The review found moderate-quality evidence for topical minoxidil, found finasteride 1 mg no better than placebo (low-quality evidence), and listed spironolactone among treatments for which further randomized trials were needed. It supplies no pooled spironolactone efficacy result. Only five of the 47 trials were at low risk of bias.

Participants / model
5,290 participants in 47 randomized trials, women with female pattern hair loss
Treatment
Mostly topical minoxidil; other interventions
Follow-up
Searched to July 2015
Study design
Cochrane systematic review (2016)
Funding
not stated in the source

It does not say spironolactone works or fails; it says more trials were needed.

Read the original source
PubMed searches, 10 October 2026: 22 records and 5 records, none testing fluid shedding or physique

PubMed search record

PubMed searches run on 10 October 2026: (1) spironolactone[tiab] AND (bodybuilder*[tiab] OR bodybuilding[tiab] OR doping[tiab] OR athlete*[tiab] OR anabolic[tiab]); (2) spironolactone[tiab] AND ("water retention"[tiab] OR "fluid retention"[tiab]) AND (healthy[tiab] OR athlete*[tiab] OR men[tiab]). 22 and 5 records returned.

The first search returned 22 records: diuretic-detection methods for doping control, rodent studies, drug-induced gynecomastia reviews, historical papers and heart failure papers. None tested spironolactone for fluid shedding or physique in healthy people, athletes or steroid users. The second search returned 5 records: reviews of resistant hypertension and cirrhotic ascites, and one randomized trial in 54 men with severe sleep apnea (DESALT, PMID 29669139, NCT01945801) in which spironolactone plus furosemide for 1 week lowered total body water by 2.2 L. That trial combined two diuretics in sleep apnea patients, so it does not test spironolactone alone in healthy people.

Participants / model
Records returned, not a population
Treatment
Not applicable
Follow-up
Searches run on 10 October 2026
Study design
Literature search
Funding
not stated in the source

A search result shows what PubMed returned on that date. It is not proof that no unindexed study exists.

Read the original source

Studies and sources

ALDACTONE label, version effective 28 November 2025: indications, RALES, warnings, PK

FDA prescribing information

DailyMed, U.S. National Library of Medicine. ALDACTONE (spironolactone) film-coated oral tablets, prescribing information, label version effective 28 November 2025. Set ID 0fed2822-3a03-4b64-9857-c682fcd462bc.

The label describes an aldosterone antagonist indicated for NYHA Class III to IV heart failure with reduced ejection fraction, add-on treatment of hypertension, edema in cirrhosis or nephrotic syndrome when other measures fail, and primary hyperaldosteronism. There is no label indication for acne, hirsutism or hair loss. In RALES (1,663 patients with heart failure, 73% male, mean spironolactone dose 26 mg a day), spironolactone reduced the risk of death by 30% (95% CI 18% to 40%), and about 9% of the male subjects developed gynecomastia; the risk rises with dose, onset ranges from 1 to 2 months to over a year, and it is usually reversible. Warnings cover hyperkalemia (with potassium monitoring), hypotension and worsening renal function, electrolyte and metabolic abnormalities, and gynecomastia. The label states spironolactone binds the androgen receptor, that its anti-androgenic properties pose a risk to the male fetus, and that feminization of male fetuses was seen in rats at 200 mg/kg a day. It is a tumorigen in rats in dietary studies, and alopecia is listed among reported adverse reactions. Peak plasma levels of spironolactone and its active metabolite canrenone come at 2.6 and 4.3 hours, food raises bioavailability (AUC) by about 95.4%, and the mean half-life is 1.4 hours for spironolactone and 16.5 hours for canrenone.

Participants / model
Adults with heart failure, hypertension, edema or hyperaldosteronism; RALES participants; rats (animal data)
Treatment
ALDACTONE film-coated oral tablets
Follow-up
Label version effective 28 November 2025
Study design
FDA prescribing information
Funding
not stated in the source

The label's heart failure, gynecomastia and PK figures come from patients and label PK participants. It gives no indication for acne, hirsutism or hair loss, and the rat findings carry no dose or route detail beyond what is stated here.

Read the original source
Drugs@FDA: ALDACTONE approved 21 January 1960

Regulatory record

U.S. Food and Drug Administration. Drugs@FDA application record for NDA 012151 (ALDACTONE). Date read from the openFDA Drugs@FDA record.

FDA first approved ALDACTONE under NDA 012151 on 21 January 1960. The sponsor on the openFDA record is Pfizer.

Participants / model
Not a clinical population
Treatment
Drug application
Follow-up
Approved 1960
Study design
FDA application record
Funding
not stated in the source

This record gives the approval date and sponsor. Indications come from the product label.

Read the original source
PATHWAY-2: 335 patients with resistant hypertension, home systolic pressure 8.70 mm Hg lower than placebo

Randomized controlled trial

Williams B et al. Lancet. 2015;386(10008):2059-2068. PMID 26414968.

Spironolactone lowered home systolic blood pressure by 8.70 mm Hg versus placebo (95% CI -9.72 to -7.69) and by 4.26 mm Hg more than the average of the other two drugs. Serum potassium exceeded 6.0 mmol/L on one occasion in 6 of 285 patients who received spironolactone.

Participants / model
335 randomized patients with drug-resistant hypertension despite three drugs at maximally tolerated doses
Treatment
Oral spironolactone 25 to 50 mg daily added to baseline drugs, versus bisoprolol, doxazosin and placebo
Follow-up
12 weeks per treatment in a crossover
Study design
Double-blind randomized crossover trial (NCT02369081)
Funding
not stated in the source

Patients with drug-resistant hypertension. The result does not describe healthy people.

Read the original source
SAFA: 410 women with acne, Acne-QoL symptom score better by 1.27 points at week 12

Randomized controlled trial

Santer M et al. BMJ. 2023;381:e074349. PMID 37192767.

The primary outcome, Acne-QoL symptom score at week 12, favored spironolactone by 1.27 points (95% CI 0.07 to 2.46), and the gap grew by week 24 (3.45, 95% CI 2.16 to 4.75). Investigator-rated treatment success at week 12 was 19% (31 of 168) versus 6% (9 of 160). Headache was more common on spironolactone (20% versus 12%, P = 0.02), and no serious adverse reactions were reported.

Participants / model
410 randomized women (mean age 29.2 years) with facial acne of at least 6 months who were judged to warrant oral antibiotics; 342 in the primary analysis
Treatment
Oral spironolactone at 50 to 100 mg daily, or matched placebo
Follow-up
Up to 24 weeks
Study design
Randomized placebo-controlled trial (ISRCTN12892056)
Funding
not stated in the source

Women only. Endpoints were Acne-QoL symptom score, self-assessed improvement, investigator global assessment and adverse reactions.

Read the original source
Acne meta-analysis: 5 trials, 563 women, objective improvement OR 6.59

Systematic review and meta-analysis

Ghanem L et al. J Cosmet Dermatol. 2025;24(8):e70411. PMID 40823723.

Objective acne improvement was higher with spironolactone (OR 6.59, 95% CI 3.50 to 12.43, I2 = 0%), while subjective assessment did not differ (OR 5.22, 95% CI 0.62 to 44.24, I2 = 85%). Menstrual irregularities (OR 1.09, 95% CI 0.37 to 3.25) and breast enlargement (OR 1.37, 95% CI 0.79 to 2.38) were not significantly different from placebo.

Participants / model
563 women with acne across 5 randomized trials, 251 of them on spironolactone
Treatment
Oral spironolactone versus placebo
Follow-up
Pooled randomized trials
Study design
2025 systematic review and meta-analysis of 5 randomized placebo-controlled trials
Funding
not stated in the source

Five trials, women only.

Read the original source
974 women on spironolactone for acne: hyperkalemia rate 0.72% versus 0.76% baseline

Human study

Plovanich M et al. JAMA Dermatol. 2015;151(9):941-4. PMID 25796182.

There were 13 abnormal potassium results in 1,802 measurements, a hyperkalemia rate of 0.72%, against a 0.76% baseline rate in a comparison group of 1,165 healthy young women (taking and not taking spironolactone); 6 of the 13 repeat tests were normal. The authors concluded that routine potassium monitoring is unnecessary for healthy women taking spironolactone for acne.

Participants / model
974 healthy young women taking spironolactone for acne at 2 US tertiary care centers; 1,165 women for the baseline rate
Treatment
Oral spironolactone; doses not stated in the abstract
Follow-up
not stated in the source
Study design
Retrospective cohort
Funding
not stated in the source

Cardiovascular disease, renal failure and renin-angiotensin drugs were exclusions, and no men were studied. The conclusion applies to that population only.

Read the original source
Cochrane review: 47 trials, 5,290 participants, no pooled spironolactone result

Systematic review and meta-analysis

van Zuuren EJ et al. Cochrane Database Syst Rev. 2016;2016(5):CD007628. PMID 27225981.

The review found moderate-quality evidence for topical minoxidil, found finasteride 1 mg no better than placebo (low-quality evidence), and listed spironolactone among treatments for which further randomized trials were needed. It supplies no pooled spironolactone efficacy result. Only five of the 47 trials were at low risk of bias.

Participants / model
5,290 participants in 47 randomized trials, women with female pattern hair loss
Treatment
Mostly topical minoxidil; other interventions
Follow-up
Searched to July 2015
Study design
Cochrane systematic review (2016)
Funding
not stated in the source

It does not say spironolactone works or fails; it says more trials were needed.

Read the original source
Pilot: 48 premenopausal women, terminal hair count not significant (P = 0.063)

Randomized controlled trial

Werachattawatchai P et al. Int J Womens Dermatol. 2025;11(3):e227. PMID 40978669.

Terminal hair count rose 9.48 versus 5.32 hairs per cm2 (P = 0.063, not significant), hair diameter rose 4.23 versus 2.96 micrometers, and moderate-to-marked global improvement was 38% versus 9% (P = 0.034). Menstrual irregularities occurred in 37.5% on spironolactone. The authors flag the small sample.

Participants / model
48 premenopausal women aged 21 to 45 with mild-to-moderate female pattern hair loss
Treatment
Oral spironolactone 100 mg daily plus topical minoxidil 3% solution, or placebo plus minoxidil
Follow-up
24 weeks
Study design
2025 randomized double-blind placebo-controlled pilot trial
Funding
not stated in the source

Minoxidil was given in both arms. Endpoints were terminal hair count, hair diameter, global photographic assessment and adverse events.

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Mixed-design meta-analysis: overall improvement rate 56.60%

Systematic review and meta-analysis

Aleissa M. Cureus. 2023;15(8):e43559. PMID 37719557.

The overall improvement rate was 56.60% (65.80% with combined therapy versus 43.21% as monotherapy), with significant heterogeneity, and 37.80% of patients had no improvement or only modest improvement. Reported adverse events included scalp pruritus or increased scurf (18.92%), menstrual disorders (11.85%) and facial hypertrichosis (6.93%).

Participants / model
Women with female pattern hair loss across mixed randomized and observational studies
Treatment
Oral spironolactone, alone or with other treatments
Follow-up
Pooled studies
Study design
2023 systematic review and meta-analysis of randomized and observational studies
Funding
not stated in the source

Pooled rates mix study designs and are not placebo-controlled effects.

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1978 study: 5 healthy men, transient testosterone rise

Human study

Tidd MJ et al. Clin Endocrinol (Oxf). 1978;9(5):389-99. PMID 152681.

Spironolactone 200 mg daily changed the pattern of plasma testosterone and LH versus placebo and raised urinary androsterone, etiocholanolone and total estrogen excretion. The authors concluded that treatment for 2 to 4 days leads to a transient rise in plasma testosterone, that continued treatment (4 to 10 days) raises LH secretion with normalized testosterone, and that androgen-to-estrogen conversion rises slightly.

Participants / model
5 healthy male volunteers
Treatment
Oral spironolactone 200 mg daily for several days, versus placebo
Follow-up
Several days
Study design
Double-blind controlled study (1978)
Funding
not stated in the source

A hormone study in 5 men at a high dose. It is not evidence of an androgen-lowering effect in healthy men.

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Evidence-based review: spironolactone definitely associated with gynecomastia

Human study

Deepinder F et al. Expert Opin Drug Saf. 2012;11(5):779-95. PMID 22862307.

The review rated the evidence for most drug associations as poor. It named spironolactone among the drugs definitely associated with gynecomastia, with anabolic steroids among those probably associated.

Participants / model
Men with drug-induced gynecomastia (review of case reports and series)
Treatment
Not drug-specific
Follow-up
Medline, EMBASE and BIOSIS searched from 1940
Study design
Evidence-based review
Funding
not stated in the source

A review of associations, not a trial.

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PubChem: spironolactone identity

Chemical identity record

National Library of Medicine. PubChem compound record CID 5833 (spironolactone).

Spironolactone: PubChem CID 5833, C24H32O4S, 416.6 g/mol, CAS 52-01-7. ALDACTONE and the generics contain spironolactone itself, not a salt. Its active metabolites include canrenone.

Participants / model
Chemical identity, not a clinical population
Treatment
Defined molecule
Follow-up
Not applicable
Study design
NLM chemical record
Funding
not stated in the source

Identity record only; it says nothing about efficacy or safety.

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Why is Spironolactone in A tier?

A fits an approved drug promoted for off-label uses and populations. Spironolactone has been FDA-approved since 1960, with a mortality benefit in heart failure and the strongest blood pressure result in resistant hypertension. Acne has randomized support in women, hair loss rests on one small pilot trial and mixed-design data, and nothing found supports use in men or for fluid shedding in healthy people.