Levonorgestrel
PLAN B
Pronunciation: lee-voe-nor-JES-trel
What it isProgestin; contraception, emergency contraception and the intrauterine system.
Why this oneThe intrauterine system gives years of contraception and treats heavy bleeding, and the emergency pill is available without prescription.
What limits itEmergency use is less effective with higher body weight and after ovulation. Irregular bleeding with the IUS.
Levonorgestrel prescription history
Animated chart of estimated U.S. prescriptions per year, Hormonal contraceptives (1960–2026). Levonorgestrel enters in 1999 (estimated).
FDA-approved for
- contraception (~1982)
Principal riskEmergency use is less effective at higher body weight
Classes and tags
Clinical profile
Legacy pregnancy categoryX
Defining liabilityVenous thromboembolism and hormone-related adverse effects; estrogen also lowers lamotrigine exposure.
FDA label
Read the full label on DailyMed ↗
NO BOXED WARNINGS
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Emergency contraception (backup after unprotected sex or contraceptive failure) | Females of reproductive potential | 1 tablet ASAP, within 72 hr | 1 tablet within 72 hr of unprotected sex | 1 tablet |
Renal Undefined
Hepatic Undefined
Use within 72 hours of unprotected sex.
Instructions
- Take as soon as possible within 72 hours (3 days) of unprotected sex — sooner is more effective.
Available strengths
- tab 1.5 mg
- IUS 13.5, 19.5, 52 mg
- system 13.5, 19.5, 52 mg
Pregnancy Undefined
Lactation Undefined
Cost
| Strength | #/mo | generic $/unit | CostPlus | |
|---|---|---|---|---|
| 1.5 mg | tab | per unit | $6.33/ea | offered |
Other forms: Levonorgestrel IUD (MIRENA)
Available combined with: ethinyl / estradiol / levonorgestrel
Generic entry2009
Open Levonorgestrel in the interactive console ↗
Memory aids: interaction avatars
Open Levonorgestrel in the interactive console ↗
Self-check
- When is levonorgestrel emergency contraception less effective?
After ovulation. - What body-size factor reduces levonorgestrel emergency-contraception efficacy?
Higher body weight.