Efficacy of different topical spironolactone treatments for acne vulgaris: A meta-analysis

Background: Topical spironolactone could serve as an alternative to oral therapy for acne vulgaris, but its efficacy requires further validation. Objectives: This study aimed to evaluate the efficacy of topical spironolactone monotherapy for acne vulgaris in systemically healthy patients. Methods: A PRISMA-compliant meta-analysis was conducted, searching PubMed, Cochrane Library, Embase, and Medline for controlled trials on exclusive topical spironolactone use. Results: Four trials (N=212) met criteria. Compared to baseline, the 5% spironolactone gel significantly reduced both Acne Severity Index (ASI; mean difference (MD) = -7.65, 95% CI [-10.63 to -4.67], p < 0.00001) and Total Lesion Count (TLC; MD = -13.50, 95% CI [-16.26 to -10.73], p < 0.00001). Similar reductions were observed with the 1% spironolactone gel (ASI; MD = -6.02, 95% CI [-7.84 to -4.20], p < 0.00001; TLC; MD = -17.60, 95% CI [-21.62 to -13.58], p < 0.00001), whereas, the 2% spironolactone solution only showed improvement in ASI (MD = -25.4, 95% CI [-39.61 to -11.91], p = 0.0005). Compared to the vehicle control, the 5% gel demonstrated efficacy in reducing both ASI (MD = -6.46, 95% CI [-9.70 to -3.23], p < 0.00001) and TLC (MD = -6.82, 95% CI [-11.67 to -1.98], p = 0.006). Conclusion: This meta-analysis demonstrates that topical spironolactone is an effective and well-tolerated monotherapy for mild-to-moderate facial acne, with its efficacy varying by formulation and concentration. These findings provide clinicians with evidence-based insights for selecting alternative topical treatments. Future studies with larger sample sizes and longer follow-up are warranted to confirm these results.