NDAVAGINALINSERT, EXTENDED RELEASE
Approved
Apr 1996
Lifecycle
LOE Approaching
Competitive Pressure
30/100
Clinical Trials
20
Data completeness
5/8 — Partial
ESTRING (estradiol) by Pfizer is estrogen receptor agonists [moa]. First approved in 1996.
Drug data last refreshed 14h ago · AI intelligence enriched 17h ago
AI summarySynthesized from FDA + DailyMed + ClinicalTrials.gov data
ESTRING is a vaginal estradiol insert approved in 1996 that delivers estrogen directly to vaginal tissue via extended-release formulation. It works as an estrogen receptor agonist to treat vaginal atrophy and related menopausal symptoms. The localized delivery minimizes systemic exposure while providing sustained hormone replacement.
$50MPart D
LOE ApproachingProduct approaching loss of exclusivity with moderate Medicare spending signals defensive positioning and smaller brand teams focused on market maintenance.
Mechanism of Action
Estrogen Receptor Agonists
Pharmacologic Class:
Estrogen
Indications
Indication data is being enriched from DailyMed and FDA labeling. Check back soon for approved therapeutic uses.
Clinical Trials (20)
Evaluate the Effect of Vimseltinib on Pharmacokinetics of Combined Oral Contraceptive (Ethinyl Estradiol/Levonorgestrel)
Started Jun 2026
24 enrolled
Healthy Participants
A Trial to Examine the Interaction of Repinatrabit With Ethinyl Estradiol/Norethindrone, Metformin,Carbamazepine, Rosuvastatin, and Methotrexate When Administered Together
Started Mar 2026
48 enrolled
Healthy Volunteers
A Phase 1 Study to Assess the Effect of ABBV-722 on Ethinyl Estradiol and Levonorgestrel Drug Levels in Healthy Adult Female Participants
Started Mar 2026
15 enrolled
Healthy Volunteer
Estradiol-mediated Inflammation and Central Sensitization in the Pathophysiology of Endometriosis-associated Pelvic Pain
Started Dec 2025
130 enrolled
EndometriosisPelvic Pain
Drug-drug Interaction Study of Bemnifosbuvir/Ruzasvir (BEM/RZR) and Ethinyl Estradiol/Levonorgestrel (EE/LNG)
Started Dec 2025
24 enrolled
Healthy Volunteer Study
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Data Sources
- Drug label: DailyMed / FDA
- Clinical trials: ClinicalTrials.gov
- Patent data: FDA Orange Book
- Spending data: CMS Medicare
The information on this page is for informational purposes only and should not be used as a substitute for professional medical advice. Drug information is sourced from FDA, DailyMed, and other government databases. Adverse event data from FAERS does not establish causation. Always consult a healthcare professional for medical decisions.