The purpose of this research study is to assess the relative bioavailability of norethindrone at different times in individuals taking 0.35mg norethindrone vs 5mg norethindrone acetate in order to demonstrate that it is safe to prescribe norethindrone acetate as a form of contraception.

There will be 9 visits/month for 2 menstrual cycles with a one month break in between the cycles. At the start of their first menstrual cycle, subjects will take norethindrone for 7 consecutive days. On each of the 7 days subjects will report to the research center for a single blood draw 1 to1.5 hours after taking the norethindrone. On Day 8 subjects will report to the research center to have an 8 hour Pharmacokinetic test in which an IV will be inserted and one tube of blood will be drawn through the IV every hour for 8 hours. Subjects will report for another single blood draw on cycle day 21. After the first cycle, the subject will wait until they have completed their next menstrual cycle and at the start of the very next menstrual cycle they will repeat the same procedure with norethindrone acetate.

$540