Reduces DHT, a hormone involved in pattern hair loss.
Female pattern hair loss becomes increasingly common after menopause. A 2022 study found that 52% of postmenopausal women experienced pattern thinning.
As estrogen falls, hormonal balance can tip toward androgens. In follicles genetically prone to thinning, an enzyme called 5-alpha reductase turns testosterone into DHT, which binds the follicle’s androgen receptors and contributes to thinning hair.
Dutasteride blocks both type I and type II forms of this enzyme, powerfully reducing the amount of DHT hair follicles are exposed to.
Clinical trials show oral dutasteride lowers DHT in the blood further than finasteride.
Mean reduction in serum DHT, in men. Dutasteride: Clark et al., J Clin Endocrinol Metab 2004 (24 weeks). Finasteride 1 mg: Drake et al., J Am Acad Dermatol 1999 (6 weeks). Separate studies.
