Generic name: Levonorgestrel
What is Plan B?
Plan B is a progestin-only emergency contraceptive pill (ECP) that can be taken after unprotected intercourse to prevent pregnancy. Plan B works by delaying or inhibiting ovulation. It is not effective once the egg has been fertilized.
Plan B is available over-the-counter for women 17 years of age and older. A prescription is required for women 16 years of age and younger.
Health Benefits
When taken as directed, Plan B is up to 89% effective in preventing pregnancy.
Plan B can be used as soon as possible after unprotected intercourse. The sooner it is taken, the better it will work.
Plan B is a safe and effective way to prevent pregnancy after unprotected intercourse.
Side Effects and Risks
The most common side effects of Plan B are nausea and vomiting. Other possible side effects include:
Abdominal pain or cramps Breast tenderness Diarrhea Dizziness Fatigue Headache Mood changes (e.g., depression)
If you experience any of these side effects, contact your doctor or healthcare provider immediately.
Plan B does not protect against sexually transmitted infections (STIs). Use condoms to reduce your risk of STI transmission.
If you are pregnant or think you may be pregnant, do not take Plan B. Plan B is not abortion and will not end a pregnancy that has already begun.
Dosages
Plan B is available as a single-dose tablet. The recommended dose is one tablet (0.75 mg levonorgestrel) taken as soon as possible after unprotected intercourse.
If you vomit within two hours of taking Plan B, contact your doctor or healthcare provider to discuss whether you need to repeat the dose.
If you are unsure about when you had unprotected intercourse or if you may have already ovulated, you can take a second dose of Plan B (0.75 mg levonorgestrel) 12 hours after the first dose. However, this may not be necessary if it has been more than five days since unprotected intercourse.
Interactions
Plan B may interact with other medications, such as:
Anticoagulants (blood thinners) Epilepsy medications HIV protease inhibitors Sedatives and tranquillizers
If you are taking any of these medications, talk to your doctor or healthcare provider before taking Plan B.
Plan B does not interact with birth control pills. However, if you vomit within two hours of taking Plan B, it may decrease the effectiveness of birth control pills. If this happens, use a backup method of contraception for at least the next seven days.
Mechanism of Action
Plan B works by delaying or inhibiting ovulation. It is not effective once the egg has been fertilized.
If taken within 72 hours of unprotected intercourse, Plan B can reduce the risk of pregnancy by up to 89%. The sooner it is taken, the better it will work.
Plan B is not abortion and will not end a pregnancy that has already begun.
Pharmacokinetics
Plan B is absorbed rapidly after oral administration. Peak plasma concentrations of levonorgestrel are reached within two hours.
Levonorgestrel is widely distributed in the body and is excreted in the urine and feces. The half-life of levonorgestrel is approximately 12 hours.
Plan B is a progestin-only emergency contraceptive pill (ECP) that can be taken after unprotected intercourse to prevent pregnancy. Plan B works by delaying or inhibiting ovulation. It is not effective once the egg has been fertilized.
Plan B is available over-the-counter for women 17 years of age and older. A prescription is required for women 16 years of age and younger.
The recommended dose of Plan B is one tablet (0.75 mg levonorgestrel) taken as soon as possible after unprotected intercourse. If you vomit within two hours of taking Plan B, contact your doctor or healthcare provider to discuss whether you need to repeat the dose.
Plan B is a safe and effective way to prevent pregnancy after unprotected intercourse. However, it is not 100% effective and should not be used as a regular method of contraception. Plan B does not protect against sexually transmitted infections (STIs). Use condoms to reduce your risk of STI transmission.
Pregnancy and Breastfeeding
Plan B is not recommended for use during pregnancy. If you are pregnant or think you may be pregnant, do not take Plan B. Plan B is not abortion and will not end a pregnancy that has already begun.
It is unknown if Plan B passes into breast milk. If you are breastfeeding, talk to your doctor or healthcare provider before taking Plan B.
