- girls who are postmenarchal or sexually active, have a negative urine pregnancy test at screening, must be using a medically acceptable method of birth control, and must agree to continue use of this method for the duration of the study (and for 2 cycles after participation in the study); acceptable methods of birth control include: barrier method with spermicide; steroidal contraceptives (oral, transdermal, implanted, or injected) in conjunction with a barrier method; intrauterine device (IUD); or abstinence