BACKGROUND: The effectiveness of different combined oral contraceptive pills and metformin in reducing hirsutism in patients with polycystic ovary syndrome (PCOS) remains unclear. OBJECTIVE: We sought to determine the effects of ethinylestradiol (35μg)/cyproterone acetate (2mg) (EE/CPA) and ethinylestradiol (20μg)/desogestrel (0.15mg) (EE/DES), alone or with metformin, on hirsutism in PCOS. METHODS: A randomized, double-blind, triple-dummy study was conducted on women with PCOS and hirsutism (N=107) who received one of four drug combinations (Arm A: EE/CPA; Arm B: EE/DES; Arm C: EE/CPA plus metformin; or Arm D: EE/DES plus metformin). Hirsutism was assessed at baseline, six months, and 12 months by using five outcomes variables. RESULTS: No outcomes variable showed a significant difference between the four arms at 12 months. There was a significant reduction in both hair density and modified Ferriman-Gallwey score (mFGS) in Arm A, mFGS in Arm B, hair density in Arm C, and diameter of sideburn hair in Arm D, respectively. Separately, there was a significant increase noted in the hair growth rate of chin and an improvement in patients’ perceptions of hirsutism in all four study arms. CONCLUSION: EE/CPA and EE/DES were equally effective in improving hirsutism in PCOS, with no added benefit from low-dose metformin. Sri Lanka Clinical Trials Registry (http://www.slctr.lk) registration no. SLCTR/2015/007.
Keywords: Hirsutism, polycystic ovary syndrome, cyproterone acetate, desogestrel, metformin, Ferriman-Gallwey score, hair growth rate, hair density, hair diameter