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Last updated: January 7, 2026

Nestorone + Estradiol Vaginal Ring

Segesterone Acetate + Estradiol Vaginal Ring

  • User: Female
  • Hormonal: Hormonal
  • Delivery type:
    • Vaginal Ring
  • Intended Duration:
    • Short-Acting
  • Development Stage: Phase II
  • Developer(s)/researcher(s): NICHD, Population Council
Details
  • API: Nestorone, Estradiol
  • Target: Progesterone Receptor
  • Mechanism of Action:
    • Ovulation Inhibition
    • Cervical Mucus Changes
    • Endometrial Changes
  • Inactive Materials: Silicone Elastomer
  • Regimen: 1 Insertion/90 Days
  • MPT: Not Potential MPT
  • Promising Attributes: E2 is not associated with an increased risk of VTE and can be protective against bone mineral loss. Nestrone is a highly effective progestin. Vaginal rings align with growing user desire for user-controlled, reversable, non-invasive methods.
Product Status

Active Clinical Research

History

2018: Results from first dose-finding study of a 90 day vaginal ring containing NES and E2 published, showing sustained release of NES at contraceptive levels but E2 release below the necessary threshold to prevent bone mineral loss
2020: Results from second dose-finding study show sustained release of both NES and E2 at appropriate levels

Publications

Additional Information