Spironolactone generally takes a few days to start working, but the full effects can take several weeks to become noticeable, depending on the condition being treated.
- For conditions like edema, spironolactone usually begins to work within 2 to 3 days, with peak effects sometimes occurring around 48 hours or more after the first dose
- For high blood pressure, it may take up to 2 weeks to see effects, though patients might not feel different even if the drug is working
- When used for acne, spironolactone typically takes longer to show benefits. Most people start seeing improvement within 4 to 8 weeks, but it can take 3 to 6 months for the full effect. Some may experience an initial worsening of acne (a "purge" phase) before improvement
The delayed onset is due to spironolactone’s mechanism of action as a mineralocorticoid receptor antagonist, which involves changes in gene expression and the activity of its active metabolites, leading to a gradual diuretic and antiandrogenic effect
. In summary:
- Edema: 2–3 days for onset
- Hypertension: up to 2 weeks
- Acne: 4–8 weeks or longer, up to 3–6 months for full effect
This timeline varies by individual and dosage.
