General model fittings of serum levonorgestrel (LNG) and ethinyl estradiol (EE) concentrations versus time. (A) LNG 150 mcg [13, 16] or 100 mcg PK profiles[14, 15]; (B) EE 30 mcg [13, 16] or 20 mcg PK profiles [14, 15]. Population predicted (PRED) profiles are shown as black lines. Subjects with different extent of obesity are shown using different colors and shapes. Subjects with BMI 18.5–24.9 kg/m2 are considered normal, BMI 25.0–29.9 kg/m2 are overweight, BMI 30.0–39.9 kg/m2 are obese, and BMI greater than 40.0 kg/m2 are extremely obese.