Research Studies

Women who meet all the following criteria are eligible for enrollment in the trial: 1. Good general overall health with no chronic medical conditions that result in periodic exacerbations requiring significant medical care. 2. Age 18-35 years, inclusive, at the enrollment visit. (Note: subjects must be at least 18 years of age to provide consent.) 3. Have a regular menstrual cycle 21-35 days in duration when not using hormonal contraception 4. Have an intact uterus and at least one ovary. 5. Consistent use of effective contraception during the preceding cycle with no unprotected intercourse since last use (NOTE: women who use oral, transdermal, vaginal, or implantable hormonal contraceptives in the preceding cycle must have discontinued hormone use at least 4 days prior to start of treatment and must not have had unprotected intercourse since discontinuing the method. Copper IUD or Levonorgestrel releasing IUD users must have discontinued IUD use at least 4 days prior to start of treatment and have experienced a spontaneous menses following IUD removal.) 6. No use of injectable contraceptives (e.g. depomedroxyprogesterone acetate) during the 10 months prior to screening unless the subject has returned to normal menses (two consecutive menses) since last injection. 7. Have a negative pregnancy test at the enrollment visit. 8. Have a diastolic blood pressure (BP) <90 mm Hg and systolic BP <140 mm Hg after 5 minutes rest in sitting position at the admission visit (below hypertension stage 2). (Note: History of hypertension stage 2 or higher, even if controlled with treatment, is exclusionary.) 9. Willing to abstain from use of non-water based (including silicone based) vaginal lubricants during the study that could adversely affect the ring, causing it to expand. 10. Understand and sign an IRB-approved informed consent form prior to screening activities (including fasting blood draws). 11. BMI &#8804; 35 kg/m2 and not having previously undergone bariatric surgery. 12. Planning to have at least one act of heterosexual intercourse without the use of another contraceptive method each month during study participation until end of treatment and at risk for pregnancy.