Topical Spironolactone is most commonly used for hormonal acne — particularly the kind that shows up along the jaw, chin, and lower face, comes back around the same point in your cycle, and doesn't fully respond to standard topical products — and for androgen-driven hair thinning when applied to the scalp. It's especially relevant for women whose acne or thinning fits a PCOS-pattern, hormonal picture. Your provider will determine whether it's appropriate for what you're experiencing.
To use it: cleanse and let your skin dry fully, apply a thin layer to the affected area once or twice daily as directed, follow with moisturizer if you're using it on your face, and pair with daily SPF in the morning. Consistency matters more than quantity — a thin, regular application works better than using more, less often.