Safety
The current Aldactone label has no boxed warning. Spironolactone can raise potassium to dangerous levels, so the label says to check potassium within 1 week of starting or changing the dose and regularly after. It is an antiandrogen: avoid it in pregnancy because of the risk to a male fetus. Breast tenderness and enlargement are possible.
Talk to a licensed clinician about your health history and every medication you take before you start.
Legal status
Prescription only; FDA-approved for other uses. Off-label for hair loss, and it needs potassium monitoring and pregnancy avoidance, so we list it with warnings.
What spironolactone for hair loss is
Spironolactone for hair loss is made by Pfizer (Aldactone). The providers we track sell it as a compounded capsule (Happy Head) or in a compounded women’s topical formula (Strut Health).
Not approved for hair loss. Spironolactone is FDA-approved for heart failure, high blood pressure, edema and primary hyperaldosteronism.
Dosing
Tablet, capsule or compounded topical, once or twice a day. Set by the prescriber. Approved tablets come in 25 mg, 50 mg and 100 mg; the label says to check potassium within a week of starting or changing the dose.
How well it works
Evidence is limited. In an open study of 80 women treated for at least 12 months with spironolactone 200 mg a day or cyproterone acetate, 44% had regrowth, 44% no clear change and 12% continued hair loss. The study had no placebo group. Individual results vary.
Spironolactone for hair loss cost
$42 to $59 a month at the providers that publish a monthly price, as of October 2026. For a full breakdown, read How much does minoxidil cost?. For the steps, read How to get a finasteride prescription online.