Study Evaluating Levonorgestrel and Ethinyl Estradiol for Oral Contraception

A Multicenter, Randomized, Open-labe, Controlled Study to Evaluate the Efficacy and Safety of the Combined Levonorgestrel(LNG) 100mcg and Ethinyl Estradiol(EE) 20mcg for Oral Contraception

The purpose of this study is to evaluate the contraceptive efficacy and safety of an oral contraceptive containing a combination of LNG 100mcg/EE 20mcg compared to LNG 150mcg/EE 30 mcg.

Inclusion Criteria:

• Healthy women,aged 20-35 years who wish to use a contraceptive.
• Women without reproductive system infection complications.
• Willingness to not use other forms of hormonal treatment.
• Three regular menstrual cycles before the study(21-35 days per cycle with 3-7 day's bleeding period, without amenorrhea or irregular bleeding).
• Signed informed consent prior to entry into the trial.

Exclusion Criteria:

• Any contraindication to the use of oral contraceptives.
• Vascular, metabolic, hepatic, renal, oncologic and other diseases.