The Efficacy and Safety of Oral and Topical Spironolactone in Androgenetic Alopecia Treatment: A Systematic Review

INTRODUCTION: Androgenetic alopecia (AGA) has negative impacts on both men and women in terms of appearance and mental stress. Spironolactone is a synthetic aldosterone receptor antagonist known to stimulate hair growth and has been widely used by dermatologists to treat AGA. OBJECTIVE: To conduct a systematic review evaluating the efficacy and safety of topical and oral spironolactone in AGA treatment. METHODS: We searched PubMed, Embase, the Cochrane Library, and the Web of Science until October 23rd, 2022, for human studies evaluating the efficacy of spironolactone for the treatment of AGA, regardless of doses and routes. RESULTS: We retrieved 784 papers and ultimately 7 articles matched our inclusion criteria and comprised 618 AGA patients (65 men, 553 women), 414 of them received spironolactone treatment. Oral spironolactone doses ranged from 25mg to 200mg daily, with the vast majority between 80mg and 110 mg. Dosage forms for topical spironolactone use include gels of 1% and solutions of 5% twice daily. Both oral and topical spironolactone have been shown efficacy for alopecia recovery, but topical use has significantly fewer side effects and is suitable for any gender. It showed better efficacy in combination with other therapies such as oral or topical minoxidil compared with monotherapy. CONCLUSION: Spironolactone is an effective and safe treatment of androgenic alopecia which can enhance the efficacy when combined with other conventional treatments such as minoxidil. Topical spironolactone is safer than oral administration and is suitable for both male and female patients, and is expected to become a common drug for those who do not have a good response to minoxidil. Furthermore, more high-quality clinical randomized controlled studies should be performed.