blood samples were taken on days 6 , 11 , 21 , and 28 of a control cycle , the third cycle of treatment with either ethinyl estradiol-levonorgestrel or ethinyl estradiol-desogestrel ( 11 volunteers each ) , the third cycle of a 3-month washout period , and the third treatment cycle after crossover change of the preparations .
C0717761
ethinyl estradiol-levonorgestrel
C0015011
ethinyl estradiol