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Plan B (Levonorgestrel)
Levonorgestrel is a synthetic progestin that prevents pregnancy primarily by inhibiting or delaying ovulation.
Levonorgestrel is a synthetic progestin that prevents pregnancy primarily by inhibiting or delaying ovulation. Used for Emergency contraception to prevent pregnancy following unprotected intercourse or contraceptive failure.
At a glance
| Generic name | Plan B (Levonorgestrel) |
|---|---|
| Sponsor | University of Pennsylvania |
| Drug class | Progestin; emergency contraceptive |
| Target | Progesterone receptor |
| Modality | Small molecule |
| Therapeutic area | Contraception / Reproductive Health |
| Phase | FDA-approved |
Mechanism of action
Levonorgestrel works as an emergency contraceptive by suppressing the luteinizing hormone (LH) surge necessary for ovulation, thereby preventing the release of an egg from the ovary. It may also alter cervical mucus and endometrial conditions to reduce sperm transport and implantation likelihood. When taken within 72 hours of unprotected intercourse, it significantly reduces the risk of pregnancy.
Approved indications
- Emergency contraception to prevent pregnancy following unprotected intercourse or contraceptive failure
Common side effects
- Nausea
- Fatigue
- Headache
- Dizziness
- Vomiting
- Abdominal pain
- Menstrual irregularities
Key clinical trials
- Clinical Research on Acute Intermittent Porphyria and the Use of Carbohydrate-Rich Diet as a Treatment (NA)
- Loxenatide Plus LNG-IUS in Endometrial Atypical Hyperplasia (PHASE2, PHASE3)
- Mirena for the Treatment of Nonatypical Endometrial Hyperplasia for 6 Months (PHASE3)
- Postplacental Copper Intrauterine Device Versus Postpartum Progesterone-only Pills on Uterine Niche Formation (NA)
- Comparison of Sequential CFA vs CFA +rFSH for Elective Fertility Preservation. (PHASE3)
- A Study of a New Way to Treat Children and Young Adults With a Brain Tumor Called NGGCT (PHASE2)
- Oral Contraceptive Pills Versus Levonorgestrel-Releasing Intrauterine System for Niche-Related Abnormal Uterine Bleeding (NA)
- Levonorgestrel-Releasing Intrauterine System With or Without Everolimus in Treating Patients With Atypical Hyperplasia or Stage IA Grade 1 Endometrial Cancer (PHASE2)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- Plan B (Levonorgestrel) CI brief — competitive landscape report
- Plan B (Levonorgestrel) updates RSS · CI watch RSS
- University of Pennsylvania portfolio CI