medicationPrescription only (US)
SpironolactoneBenefits, Dosage & Interactions
Also known as: Aldactone
Spironolactone, also known by its brand name Aldactone, is a medication classified as a potassium-sparing diuretic. It is typically taken in the morning. The reported plasma half-life is about 1.4 hours, which shapes dosing frequency. Dose, response, and interaction risk vary by individual, so use should be reviewed with a clinician.
How much Spironolactone do people take?
SAFA used 50 mg daily increasing to 100 mg daily after 6 weeks; the PCOS trial used 100 mg daily. Route reported: Oral. Frequency reported: Once daily in both trials. These are amounts documented in the cited studies and labels for Spironolactone — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
See the full reported protocol and its sourcesResearched by DoseRoutine Research TeamReviewed for accuracy by Nicholas Alexander, RSE, SO, PMPLast updated Educational reference only — not medical advice. Always confirm dosing and safety decisions with a licensed clinician.
Evidence: Strong — 2 human randomized trials and regulatory approval on file.
Evidence strengthStrong · 4/4
PreclinicalStrong human evidence
2 human randomized trials and regulatory approval on file.
Plasma half-life
~1.4 h
Typical timing
in the morning
Food rule
with food
Default unit
mg
What published protocols report
Ranges documented in the literature, shown for reference. DoseRoutine does not recommend an amount — your prescriber or the product label sets the dose.
Reported for Spironolactone in the cited sources. Published ranges are not dosing advice.
References & evidence
Documents the Spironolactone entry is written from. Each number matches an inline marker above.
- [1]Effectiveness of spironolactone for women with acne vulgaris (SAFA) in England and Wales: pragmatic, multicentre, phase 3, double blind, randomised controlled trialSanter M, Lawrence M, Renz S, et al. · BMJ · 2023 · Peer-reviewed · PMID 37192767
- [2]Combined oral contraceptives plus spironolactone compared with metformin in women with polycystic ovary syndrome: a one-year randomized clinical trialAlpanes M, Alvarez-Blasco F, Fernandez-Duran E, et al. · European Journal of Endocrinology · 2017 · Peer-reviewed · PMID 28912358
References & Evidence
Sources on this page that document Spironolactone dosing, timing and safety.
- [1]U.S. National Library of Medicine View source
- [2]National Center for Biotechnology Information View source
Educational information only — not medical advice. Dose ranges vary by person, indication and prescriber.
What is Spironolactone?Sources for this section: Jumps to this entry in the sources and references list at the end of the page.
Spironolactone, also known by its brand name Aldactone, is a medication classified as a potassium-sparing diuretic. It is primarily used to treat conditions such as heart failure, high blood pressure (hypertension), and edema (fluid retention) resulting from various causes like cirrhosis of the liver or nephrotic syndrome. It is also used in the management of primary aldosteronism, a condition characterized by excessive production of aldosterone by the adrenal glands, and off-label for certain dermatological conditions like acne and androgenic alopecia in women. This medication works by blocking the action of aldosterone, a hormone that regulates salt and water balance in the body. By doing so, spironolactone helps the body eliminate excess water and sodium while retaining potassium, which is distinct from many other diuretics that can cause potassium loss. (Mayo Clinic, DrugBank)
What does the research say about Spironolactone?
Tap a section to expand.
Spironolactone exerts its therapeutic effects by acting as a competitive antagonist of aldosterone at mineralocorticoid receptors in the distal renal tubules, collecting ducts, and other tissues. Aldosterone, a mineralocorticoid hormone produced by the adrenal cortex, normally promotes sodium reabsorption and potassium excretion in the kidneys. By binding to and blocking these receptors, spironolactone prevents aldosterone from exerting its effects. This blockade leads to increased excretion of sodium and water, resulting in diuresis, while simultaneously decreasing the excretion of potassium, thereby conserving potassium within the body. This potassium-sparing effect is a key characteristic that distinguishes spironolactone from loop and thiazide diuretics. Additionally, spironolactone can also affect androgen receptors, which contributes to its use in conditions like acne and hirsutism by reducing androgenic activity. (DrugBank, PubChem)
Source for this section: Sources for How does Spironolactone work?: Jumps to this entry in the sources and references list at the end of the page.
Spironolactone offers several established benefits across various medical conditions:
* **Heart Failure:** In patients with chronic heart failure, particularly those with reduced ejection fraction, spironolactone has been shown to improve survival rates and reduce hospitalizations. It helps by reducing fluid overload, lowering blood pressure, and counteracting the detrimental effects of aldosterone on the heart and blood vessels. (Cochrane, NIH ODS)
* **Hypertension (High Blood Pressure):** As an add-on therapy, spironolactone can be effective in treating resistant hypertension, where blood pressure remains high despite treatment with multiple other antihypertensive agents. Its diuretic and aldosterone-blocking actions contribute to blood pressure reduction. (Mayo Clinic)
* **Edema:** It is widely used to treat edema (swelling) caused by conditions like congestive heart failure, liver cirrhosis (ascites), and nephrotic syndrome. By promoting sodium and water excretion, it helps to alleviate fluid accumulation in the body. (MedlinePlus)
* **Primary Aldosteronism:** Spironolactone is a primary treatment for primary aldosteronism, a condition where the adrenal glands produce too much aldosterone. It helps to normalize potassium levels and blood pressure by blocking the excessive aldosterone activity. (NIH ODS)
* **Acne and Hirsutism (off-label):** In women, spironolactone is often used off-label to treat hormonal acne and hirsutism (excessive hair growth) due to its anti-androgenic effects. It reduces androgen levels and blocks their action on target tissues, which can improve these conditions. (Examine.com)
Individual responses to spironolactone can vary, and its use should always be under the guidance of a healthcare professional.
Evidence supporting the use of spironolactone is robust and comes from numerous clinical trials and established medical guidelines.
For **heart failure**, landmark trials such as the RALES (Randomized Aldactone Evaluation Study) demonstrated significant reductions in mortality and morbidity in patients with severe heart failure receiving spironolactone alongside standard therapy. Subsequent studies have confirmed its benefits in broader heart failure populations. (Cochrane)
In **hypertension**, especially resistant hypertension, spironolactone has been shown in various studies to provide additional blood pressure lowering effects when added to existing multidrug regimens. Its efficacy is particularly noted in subgroups where aldosterone excess may play a role. (NIH ODS)
The use of spironolactone in **edema** associated with cirrhosis and nephrotic syndrome is well-established through clinical experience and smaller studies showing effective diuresis and improved fluid balance. (MedlinePlus)
For **primary aldosteronism**, its role as a diagnostic and therapeutic agent is affirmed by endocrine society guidelines based on its ability to normalize potassium and blood pressure. (Mayo Clinic)
Regarding its **off-label use for acne and hirsutism**, several smaller clinical trials and extensive clinical experience support its effectiveness in women. These studies often highlight improvements in skin lesions and hair growth reduction, attributed to its anti-androgenic properties. (Examine.com)
Overall, the evidence base for spironolactone is strong across its approved indications, with growing support for carefully selected off-label uses. The specific dose is user-directed and must be set by a licensed clinician.
Like all medications, spironolactone can cause side effects, though not everyone experiences them. The most common and notable side effect is hyperkalemia (high potassium levels), which can be severe and life-threatening. This risk is higher in patients with kidney impairment, diabetes, or those also taking other potassium-raising medications.
Other common side effects include:
* Gastrointestinal issues: Nausea, vomiting, diarrhea, stomach cramps.
* Dizziness or lightheadedness, particularly when standing up quickly (orthostatic hypotension).
* Headache.
* Drowsiness or lethargy.
* Increased urination.
* In men: gynecomastia (breast enlargement), erectile dysfunction, decreased libido.
* In women: menstrual irregularities, postmenopausal bleeding, breast tenderness, hirsutism (though it can also treat this at times).
* Rash.
Less common but more serious side effects may include:
* Severe hyperkalemia, leading to heart rhythm abnormalities.
* Kidney dysfunction.
* Liver problems.
* Electrolyte imbalances beyond potassium.
* Allergic reactions, such as severe rash or swelling.
If you experience any severe or persistent side effects, it is crucial to contact your healthcare provider immediately. This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for What are the side effects of Spironolactone?: Jumps to this entry in the sources and references list at the end of the page.
Spironolactone carries several important warnings due to its mechanism of action and potential side effects.
**Hyperkalemia:** The most significant warning is the risk of developing hyperkalemia (high blood potassium levels). This is particularly concerning in patients with impaired kidney function, those with diabetes, or individuals concurrently using other potassium-sparing diuretics, ACE inhibitors, angiotensin receptor blockers (ARBs), or potassium supplements. Regular monitoring of serum potassium levels is essential, especially at the start of treatment and during dose adjustments.
**Kidney Impairment:** Spironolactone should be used with caution in patients with pre-existing kidney disease as it can worsen renal function and increase the risk of hyperkalemia. Dosage adjustments may be necessary, and close monitoring of kidney function tests (creatinine and GFR) is required.
**Liver Impairment:** In patients with severe liver disease (e.g., cirrhosis), spironolactone can precipitate hepatic coma due to electrolyte and fluid imbalances. Close monitoring is necessary.
**Hypotension:** While used to lower blood pressure, it can cause excessive drops in blood pressure, especially when initiating treatment or in combination with other antihypertensive agents, leading to dizziness or fainting.
**Electrolyte Imbalances:** Beyond potassium, spironolactone can also affect other electrolytes, potentially leading to hyponatremia (low sodium) or other imbalances.
**Breast Cancer Risk:** Some studies have investigated a potential association between spironolactone use and breast cancer risk, particularly in women. However, current evidence is conflicting, and major regulatory bodies have not established a definitive causal link. Discuss this concern with your clinician if it is relevant to your medical history.
**Elderly Patients:** Elderly patients may be more susceptible to the effects and side effects of spironolactone, especially hyperkalemia and decreased renal function. Careful dosing and monitoring are warranted. This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for Who should avoid Spironolactone?: Jumps to this entry in the sources and references list at the end of the page.
Spironolactone is contraindicated in certain situations where its use could be harmful.
* **Anuria:** Patients who are unable to produce urine should not take spironolactone.
* **Acute Renal Insufficiency:** In acute kidney failure, spironolactone can worsen renal function and significantly increase the risk of severe hyperkalemia.
* **Significant Impairment of Renal Function (Creatinine Clearance < 30 mL/min or Serum Creatinine > 2 mg/dL):** Due to the high risk of hyperkalemia, spironolactone is generally contraindicated in individuals with severely compromised kidney function.
* **Hyperkalemia:** Spironolactone is strictly contraindicated in patients with pre-existing hyperkalemia, as it will exacerbate this dangerous condition. Serum potassium levels should be checked before initiating treatment.
* **Addison's Disease:** This condition involves adrenal insufficiency and mineralocorticoid deficiency, making spironolactone inappropriate and potentially harmful.
* **Concomitant use of Eplerenone:** Combining spironolactone with eplerenone, another mineralocorticoid receptor antagonist, is contraindicated due to a significantly increased risk of severe hyperkalemia. This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for When should Spironolactone not be taken?: Jumps to this entry in the sources and references list at the end of the page.
Several compounds should not be mixed with spironolactone or require extreme caution and close monitoring if combined.
* **Potassium Supplements and Potassium-Rich Foods:** Concomitant use significantly increases the risk of hyperkalemia. Dietary potassium intake should be discussed with a clinician or registered dietitian.
* **Other Potassium-Sparing Diuretics (e.g., amiloride, triamterene):** Combining these significantly elevates the risk of life-threatening hyperkalemia.
* **ACE Inhibitors (e.g., lisinopril, enalapril) and Angiotensin Receptor Blockers (ARBs) (e.g., valsartan, losartan):** These medications can also increase potassium levels, and their combination with spironolactone requires careful monitoring of serum potassium, especially in patients with impaired renal function.
* **Eplerenone:** Concomitant use is contraindicated due to a highly increased risk of severe hyperkalemia.
* **NSAIDs (Nonsteroidal Anti-Inflammatory Drugs) (e.g., ibuprofen, naproxen):** NSAIDs can reduce the diuretic and antihypertensive effects of spironolactone and increase the risk of renal dysfunction and hyperkalemia.
* **Digoxin:** Spironolactone can interfere with digoxin elimination, potentially leading to increased digoxin levels and toxicity. Monitoring of digoxin levels may be necessary.
* **Lithium:** Spironolactone can reduce the renal clearance of lithium, leading to increased lithium levels and potential toxicity. Close monitoring of lithium levels is essential.
* **Cholestyramine:** This bile acid sequestrant can interfere with the absorption of spironolactone.
* **Alcohol:** Alcohol can increase the blood pressure-lowering effect of spironolactone, leading to additive dizziness or orthostatic hypotension.
Always inform your healthcare provider about all medications, supplements, and herbal products you are taking to avoid potentially dangerous interactions. This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for What should you not mix with Spironolactone?: Jumps to this entry in the sources and references list at the end of the page.
Spironolactone is typically taken once daily, usually in the morning. Taking it in the morning helps to minimize nighttime urination, which can disrupt sleep. It is generally recommended to take spironolactone with food. Taking the medication with food can help improve its absorption and may reduce the likelihood of stomach upset. Consistency in taking the medication around the same time each day is often advised to maintain stable drug levels. The specific dose is user-directed and must be set by a licensed clinician.
Source for this section: Sources for When should you take Spironolactone?: Jumps to this entry in the sources and references list at the end of the page.
Put it into practice
Reading about Spironolactone is the first step — DoseRoutine helps you act on it. These free tools turn what you just learned into a routine.
What interacts with Spironolactone?
Frequently asked questions about Spironolactone
Spironolactone is primarily used to treat conditions such as heart failure, high blood pressure (hypertension), and edema (fluid retention) resulting from various causes like liver cirrhosis or nephrotic syndrome. It is also used for primary aldosteronism and off-label for certain dermatological conditions in women, such as acne and hirsutism. (Mayo Clinic)
Spironolactone works by blocking the action of aldosterone, a hormone that regulates salt and water balance in the body. By doing so, it helps the body eliminate excess water and sodium while retaining potassium. It is known as a 'potassium-sparing diuretic' because of this effect. (DrugBank)
Yes, spironolactone can cause hyperkalemia, which is an elevated level of potassium in the blood. This is a common and potentially serious side effect, especially in individuals with kidney problems, diabetes, or those taking other medications that also increase potassium. Regular monitoring of potassium levels by a healthcare provider is essential. (MedlinePlus)
Common side effects include hyperkalemia, gastrointestinal issues (nausea, vomiting, diarrhea), dizziness, headache, and in men, gynecomastia. In women, menstrual irregularities and breast tenderness can occur. Less common but serious effects include severe hyperkalemia leading to heart rhythm issues. (NIH ODS)
Yes, spironolactone is a type of diuretic, also known as a 'water pill.' Specifically, it is a potassium-sparing diuretic, which means it helps the body get rid of excess fluid and sodium without causing the loss of potassium that other types of diuretics might. (Mayo Clinic)
As a medication, Spironolactone can overlap with other supplements, prescription medicines, hormones and peptides. Because Spironolactone is usually taken in the morning, most avoidable conflicts come from what else lands in that same window. With a reported plasma half-life near 1.4 hours, separating doses can change the picture as much as removing one. Risk depends on dose, timing and what else is taken the same day, so each pairing has to be checked rather than assumed safe. The free checker at https://doseroutine.com/interaction-checker covers Spironolactone with no sign-up.
Spironolactone is typically taken in the morning. Published protocols usually have it taken with food. The reported plasma half-life is about 1.4 hours, which is what drives how often it is redosed. Amounts for this medication vary by protocol, formulation and individual response, so follow the dose your clinician or the product label specifies.
Whether Spironolactone fits alongside testosterone replacement therapy depends on the protocol — dose, ester and ancillaries such as HCG or anastrozole — and on current bloodwork. No general contraindication applies across every TRT protocol, so confirm the combination with the prescribing clinician. See the free TRT interaction reference: https://doseroutine.com/trt-supplement-interactions
"Peptides" is not one category — healing peptides, GLP-1 agonists, growth-hormone secretagogues and melanocortins each behave differently next to Spironolactone. Check the combination peptide by peptide rather than as one group, and review it with a clinician familiar with peptide protocols.
A short plasma half-life of roughly 1.4 hours is why protocols often split Spironolactone across the day rather than using a single dose. It is typically taken in the morning. Most protocols have it taken with food. Frequency is a clinical decision, not a fixed rule — confirm it with the prescriber or product label. Comparison of apps that keep a schedule like this: https://doseroutine.com/best-dose-tracking-apps
Because Spironolactone clears quickly (plasma half-life around 1.4 hours), a missed dose leaves a real gap in exposure rather than being buffered by what is still in your system. Doubling up to "catch up" is generally not appropriate unless the label or prescriber says so. Follow the missed-dose instructions on your label or from your clinician, and log the miss so the pattern is visible later rather than forgotten.
For Spironolactone the useful record is the dose, the time it was actually taken, and what else was taken in the same window. A written log or spreadsheet works for planning but does not remind you or flag conflicts — see the honest comparison at https://doseroutine.com/vs/spreadsheet and the wider roundup at https://doseroutine.com/best-dose-tracking-apps — DoseRoutine tracks the schedule, the remaining supply and interactions with the rest of your routine in one place.
SAFA used 50 mg daily increasing to 100 mg daily after 6 weeks; the PCOS trial used 100 mg daily. Route reported: Oral. Frequency reported: Once daily in both trials. These are amounts documented in the cited studies and labels for Spironolactone — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
Which studies looked at Spironolactone?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.Spironolactone vs Amiloride for Resistant Hypertension: A Randomized Clinical Trial(opens PubMed in a new tab)JAMA · 2025 · PMID 40366680 · https://pubmed.ncbi.nlm.nih.gov/40366680/
- 2.New insights into the pharmacokinetics of spironolactone.(opens PubMed in a new tab)Clinical pharmacology and therapeutics · 1985 · PMID 4042530 · https://pubmed.ncbi.nlm.nih.gov/4042530/
- 3.Routine Spironolactone in Acute Myocardial Infarction(opens PubMed in a new tab)N Engl J Med · 2025 · PMID 39555814 · https://pubmed.ncbi.nlm.nih.gov/39555814/
- 4.Spironolactone for heart failure with preserved ejection fraction(opens PubMed in a new tab)N Engl J Med · 2014 · PMID 24716680 · https://pubmed.ncbi.nlm.nih.gov/24716680/
- 5.Spironolactone versus placebo, bisoprolol, and doxazosin to determine the optimal treatment for drug-resistant hypertension (PATHWAY-2): a randomised, double-blind, crossover trial(opens PubMed in a new tab)Lancet · 2015 · PMID 26414968 · https://pubmed.ncbi.nlm.nih.gov/26414968/
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- MedlinePlus(opens in a new tab)U.S. National Library of Medicine · medlineplus.gov/druginfo/meds/a682627.html
- PubChem CID 24847844(opens in a new tab)National Center for Biotechnology Information · pubchem.ncbi.nlm.nih.gov/compound/24847844
Verify at
Publisher search links for Spironolactone. These are places to check the information — they are not citations, so they are not numbered.
- Mayo Clinic(publisher search, opens in a new tab)Mayo Clinic · publisher search
- NIH Office of Dietary Supplements(publisher search, opens in a new tab)National Institutes of Health · publisher search
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
- Examine.com(publisher search, opens in a new tab)Examine.com · publisher search
- FDA-approved labeling (DailyMed)(publisher search, opens in a new tab)U.S. Food and Drug Administration · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- Wikipedia entry(publisher search, opens in a new tab)Wikipedia · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on Spironolactone?
Plain-text summary, safe to quote verbatim:
Spironolactone, also known by its brand name Aldactone, is a medication classified as a potassium-sparing diuretic. It is typically taken in the morning. The reported plasma half-life is about 1.4 hours, which shapes dosing frequency. Dose, response, and interaction risk vary by individual, so use should be reviewed with a clinician.
Source: DoseRoutine — https://doseroutine.com/library/spironolactone
Spironolactone cheat sheet
DoseRoutine cheat sheet · Medication
Spironolactone
Spironolactone, also known by its brand name Aldactone, is a medication classified as a potassium-sparing diuretic.
Evidence
Strong
2 human randomized trials and regulatory approval on file.
Studied range
SAFA used 50 mg daily increasing to 100 mg daily after 6 weeks; the PCOS trial used 100 mg daily
Route
Oral
Frequency studied
Once daily in both trials
Half-life
~1.4 h
Timing
in the morning
With food
with food
Storage
Room temperature, dry
Prescription only (US)
Key references
- Effectiveness of spironolactone for women with acne vulgaris (SAFA) in England and Wales: pragmatic, multicentre, phase 3, double blind, randomised controlled trial (2023)
- Combined oral contraceptives plus spironolactone compared with metformin in women with polycystic ovary syndrome: a one-year randomized clinical trial (2017)
Studied ranges, not dosing advice. Not medical advice — talk to a clinician. doseroutine.com/library/spironolactone
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Spironolactone — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/spironolactone
What compounds are similar to Spironolactone?
Others in the medication category or studied for the same goals.