Even if the incidence of persistent sexual adverse events is 3% to 5%… approximately 900,000 to 1.5 million men would suffer persistent sexual and psychiatric adverse events.

[A]pproximately 30 million young men, worldwide, would be prescribed finasteride or dutasteride to treat male pattern hair loss. Even if the incidence of persistent sexual adverse events is 3% to 5%, which may be viewed as a small number, approximately 900,000 to 1.5 million men would suffer persistent sexual and psychiatric adverse events. By no means this would be considered a small number and should not be dismissed or ignored.

—Post-finasteride syndrome: a surmountable challenge for clinicians: Fertility and Sterility, January 2020