What is oral levonorgestrel, and how does it work (mechanism of action)?
- Levonorgestrel (Plan B) is emergency contraception (commonly called the morning after pill) that is used as backup contraception to prevent pregnancy when taken within 72 hours after unprotected sex or when birth control fails.
- Levonorgestrel is a progestin. Progestins are hormones used in many birth control pills. Although levonorgestrel and similar emergency contraception pills contain a higher dose of levonorgestrel than birth control pills, they work in a similar way to prevent pregnancy, mainly by stopping the release of an egg from the ovary. Additionally, levonorgestrel also may prevent fertilization of an egg (the uniting of the sperm with the egg) or prevent the attachment (implantation) of a fertilized egg to the uterus (womb).
- Emergency contraception pills do not work in women who are already pregnant and should not be taken during pregnancy.
- The FDA approved levonorgestrel in July 1999.
What brand names are available for levonorgestrel-oral?
Plan B One-Step, Next Choice One Dose, My Way
Is levonorgestrel-oral available as a generic drug?
GENERIC AVAILABLE: Yes
Do I need a prescription for levonorgestrel-oral?
No. Most emergency contraception pills can be purchased over-the-counter or OTC (without a prescription). However, some age restrictions may apply.
What are the uses for oral levonorgestrel?
Emergency contraception pills are used to help prevent pregnancy after unprotected sex or when birth control methods fail. Emergency contraception is a backup method of preventing pregnancy and should not be used routinely.
What are the side effects of oral levonorgestrel?
Side effects include:
- Menstrual changes
- Nausea
- Lower stomach (abdominal) pain
- Tiredness
- Headache
- Dizziness
- Vomiting
- Breast pain
What is the dosage for oral levonorgestrel?
- Emergency contraception pills should be taken as soon as possible and not more than 72 hours after unprotected sex or when birth control fails.
- Single dose regimen: Take one 1.5 mg tablet as soon as possible within 72 hours of unprotected sex or when birth control fails.
- Two-dose regimen: Take one 0.75 mg tablet as soon as possible within 72 hours of unprotected sex or when birth control fails, followed by a second 0.75 mg tablet 12 hours later.
Which drugs or supplements interact with oral levonorgestrel?
Drugs or herbal products that increase the activity certain liver enzymes that breakdown drugs may reduce blood levels of levonorgestrel and the effectiveness of the morning after pill.
Is oral levonorgestrel safe to take if I’m pregnant or breastfeeding?
- Emergency contraception pills will not work if you are already pregnant and should not be used during pregnancy.
- Levonorgestrel is thought to enter human milk after oral administration and should be used cautiously in nursing mothers.
What else should I know about oral levonorgestrel?
What preparations of levonorgestrel-oral are available?
- Levonorgestrel is available as a blister pack containing two 0.75 mg tablets
- Plan B One-Step, Next Choice One Dose, My Way are available as a blister pack containing one 1.5 mg tablet
How should I keep levonorgestrel-oral stored?
Levonorgestrel should be stored at room temperature between 15 C and 30 C (59 F and 86 F).