Emergency Contraception and Body Weight: Pilot Study
Emergency Contraception and Body Weight: Pilot Study
The purpose of this research study is to determine how body weight changes the drug level of
 an emergency contraceptive pill containing a hormone called levonorgestrel (LNG). This
 emergency contraceptive is available to women without a prescription, but has recently been
 found to not work as well to prevent pregnancies in women of higher body weight. The overall
 goal of this research is to improve the effectiveness of contraception for women, no matter
 their weight.
To determine if differences exist in the pharmacokinetics (PK) of levonorgestrel-based
 emergency contraception (LNG-EC) in obese and normal body mass index (BMI) users and test
 whether doubling the dose of LNG-EC in obese women increases total and free LNG serum
 concentrations.

 We enrolled healthy, reproductive-age women with obese and normal BMIs received 1.5 mg LNG
 orally and then in a subsequent menstrual cycle, the obese group also received 3 mg LNG.
 Total and free LNG PK parameters were obtained via serum samples through an indwelling
 catheter at 0, 0.5, 1, 1.5, 2, and 2.5 h. The primary outcome was the difference in total and
 free LNG concentration maximum (Cmax) between ECx1 and ECx2 in the obese group.
Inclusion Criteria:

 -  Subjects are between the ages of 18 and 35

 -  Subjects are in good general health

 -  Subjects have regular menstrual cycles (between 21 and 35 days)

 -  Subjects are willing to use condoms (if you are sexually active with a male partner),
 subjects are willing to not have sex with men during the study, or subjects have had a
 tubal ligation (or have a partner who has had a vasectomy) or subjects have a copper
 intrauterine device (IUD).

 Exclusion Criteria:

 -  Metabolic disorders including uncontrolled thyroid dysfunction and Polycystic Ovarian
 Syndrome

 -  Impaired liver or renal function

 -  Actively seeking or involved in a weight loss program (must be weight stable)

 -  Pregnancy, breastfeeding, or seeking pregnancy; recent (8 week) use of hormonal
 contraception

 -  Current use of drugs that interfere with metabolism of sex steroids

 -  Smokers.