Spironolactone: What it is and how it helps

Spironolactone is a prescription medication used as a potassium-sparing diuretic and an anti-androgen. Doctors prescribe it for fluid buildup from heart failure, liver disease, or kidney problems, for high blood pressure, and off-label for acne or unwanted hair in women. It lowers fluid and blocks some effects of male hormones, which is why it helps both swelling and hormone-related skin issues.

How spironolactone works

The medicine blocks aldosterone, a hormone that tells your kidneys to hold sodium and water. By blocking aldosterone, spironolactone helps your body excrete extra fluid while keeping potassium. It also weakly blocks androgen receptors, which reduces oil production and slows hair growth. Effects start within days for fluid control; skin and hair results can take weeks to months.

Common side effects and safety tips

Watch for symptoms of high potassium (hyperkalemia): muscle weakness, numbness, or an irregular heartbeat. Other common effects include dizziness, low blood pressure when standing, breast tenderness or enlargement in men, and changes to menstrual periods. Dehydration and low sodium can happen if you lose too much fluid. Don’t combine spironolactone with potassium supplements, salt substitutes that contain potassium, or other potassium-sparing drugs unless a doctor tells you to.

Before you start, your provider should check your kidney function and potassium level. Typical starting doses vary by condition: low doses for acne (often 25–100 mg daily) and higher doses for heart or blood pressure issues. Always follow your prescriber's instructions—doses are individualized.

Interactions matter. ACE inhibitors, ARBs, NSAIDs, and some blood pressure medicines can raise potassium or affect kidneys when taken with spironolactone. Tell your doctor about all medications, supplements, and herbal products you use. If you have kidney disease, diabetes, or low blood pressure, your doctor may choose another treatment or monitor labs more often.

Avoid spironolactone during pregnancy. It can affect fetal development. Breastfeeding decisions should be discussed with your clinician because the drug can pass into milk. If you plan to get pregnant, talk to your doctor about safer options.

How to take it: take spironolactone with or without food, at the same time each day. If you feel lightheaded, stand up slowly and avoid hot tubs or heavy exercise until you know how it affects you. Keep routine blood tests—usually within one to two weeks after starting and periodically after that—to check potassium and kidney function.

If you notice symptoms like severe belly pain, fainting, very fast or slow heartbeat, extreme tiredness, or signs of allergic reaction, seek medical help right away. For milder issues like dizziness or breast changes, call your prescriber to discuss dose changes or alternatives.

Spironolactone works well for many people when used correctly. Good monitoring and clear communication with your healthcare team keep it safe. If you have questions about how it fits with other meds or conditions, ask your provider—they’ll guide you to the best plan for you.