YAZ, Oral Contraceptive Registration in China

Inclusion Criteria: * Healthy women between 18 and 45 requesting oral contraception. * Smokers may not exceed 30 years of age. Exclusion Criteria: * The use of steroidal oral contraceptives , or any drug that could alter oral contraception metabolism will be prohibited during the study. * Pregnancy, lactation (less than 3 menstrual cycles since delivery, abortion or lactation before start of treatment) * Menstrual disorders suspicious of ovarian failure (e.g. oligomenorrhea, amenorrhea, hypomenorrhea * Any disease or condition that may worsen under hormonal treatment * Other contraceptive methods such as sterilization or IUD/IUS * Substantial overweight (BMI \> 30 kg/m2).