Sublingual minoxidil increases hair thickness in men with hair loss.
January 2022 in “Journal of Cosmetics, Dermatological Sciences and Applications” The serum increased hair density and was well-tolerated, but didn't affect hair thickness or shedding.
53 citations,
August 2019 in “Journal of The American Academy of Dermatology” Oral minoxidil and topical minoxidil 5% both effectively improve female-pattern hair loss with safe side effects.