Intended for emergency contraception to support pregnancy prevention following unprotected intercourse or contraceptive failure.
Mechanism of Action
This synthetic progestogen inhibits ovulation by suppressing the mid-cycle surge of luteinizing hormone. It may also alter cervical mucus consistency to impede sperm transport or prevent fertilization.
Route of Administration
Oral
Onset Time
1–2 hours
Duration
2–3 days
Contraindications
Hypersensitivity to levonorgestrel, Confirmed pregnancy, Unexplained vaginal bleeding
Severe Adverse Events
Ectopic pregnancy, Severe abdominal pain — requires immediate medical attention
Common Side Effects
Nausea, Fatigue, Headache
Uncommon Side Effects
Menstrual changes, Breast tenderness, Dizziness
Drug Interactions
Rifampin, St. John's Wort, Phenytoin, Carbamazepine, Tobacco
Pregnancy Safety Warnings
FDA Category X: Contraindicated during pregnancy. Breastfeeding: Small amounts excreted in milk; wait 24 hours after dose to nurse.
Age Restrictions
Clinically recognized for use in females of reproductive potential.
Information related to Plan B is compiled and periodically reviewed with reference to established medical sources and prescribing guidance. Content is provided for general reference and should be confirmed with a registered healthcare professional before use.
