Dutasteride is an antiandrogen that inhibits both 5α-reductase isoenzymes 1 and 2, reducing conversion of testosterone to dihydrotestosterone. Dutasteride is not licensed for female pattern hair loss but there are anecdotal reports of its successful use in the treatment of female and male pattern hair loss.
A retrospective questionnaire was sent to 28 female patients prescribed dutasteride for female pattern hair loss to evaluate efficacy and side effects, of whom 20 responded and 19 had taken the medication.
Out of 12 patients who took this treatment for more than twelve months, eight were either very satisfied (4) or somewhat satisfied (4). Ten patients noticed a decrease in hair loss, of whom eight noticed some hair re-growth. Two patients noticed reduced hirstutism, one of whom found that the improvement was not maintained in spite of continuing the medication. Of those four patients who had been on the medication 24 months or longer, three reported they were very satisfied and one somewhat satisfied
Seven patients took the dutasteride for less than one year. In these cases, the reasons given for stopping were lack of effect in four cases, and side effects in four cases. The commonest side effects in all groups were breast tenderness (5), loss of libido (4), and weight change (2).
These results support the anecdotal evidence for the use of dutasteride in the treatment of female pattern hair loss. Further well constructed randomised control trials, with objective measures of hair density and regrowth are needed to fully evaluate this treatment.