Cyproterone acetate for severe hirsutism:results of a double‐blind dose‐ranging study*

In a study from 1991, 60 hirsute women were treated with varying doses of cyproterone acetate (CPA) to determine if there was a dose-response relationship. The study was a double-blind dose-ranging trial over 12 months, where patients received either the Dianette contraceptive pill containing 35μg ethinyl estradiol and 2mg CPA, Dianette plus an additional 20mg CPA, or Dianette plus an additional 100mg CPA. Hair growth was assessed using the Ferriman and Gallwey clinical scale and by measuring hair shaft diameter and linear growth. Out of the initial participants, 38 completed the study, 8 withdrew due to side effects, and 14 were lost to follow-up. All doses significantly reduced clinical hair growth scores, with reductions observed as early as 3 months for the higher doses. Hair diameter was reduced by all doses after 12 months, with no significant differences between the doses, although there was a trend suggesting a dose response for hair diameter reductions on the forearm, abdomen, and thigh. There were no significant reductions in daily linear growth rates. The study concluded that 2mg of CPA daily is as effective as higher doses for treating hirsutism in women.