This article will discuss how long these side effects may last and what can be done to alleviate them.
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What Is Plan B and How Does It Work?
Plan B is an emergency contraceptiveavailable over-the-counter (OTC) without a prescription or ID.

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It can prevent pregnancy after unprotected sex or birth control failure.
The medication comes in an aluminum foil blister package containing one 1.5 milligram (mg) tablet of levonorgestrel.
It will not work if you are already pregnant and will not affect an existing pregnancy.
How Long Do Plan B Side Effects Last?
Plan B One-Step is safe when used as directed.
Although side effects may occur, they are typically mild and temporary, usually passing within 24 hours.
Consult your pharmacist for options to reduce nausea or relieve pain.
Seek medical attention immediately if experiencing severelower abdominal painthree to five weeks after taking Plan B One-Step.
You may experience these side effects mildly, but they typically pass within 24 hours.
OTC medication can help ease symptoms.
See medical attention if symptoms persist for more than 48 hours or are severe.
Plan B is not intended for regular use.Consult with your healthcare provider about alternative birth control methods.
Using an alternative method of birth control is important as Plan B will not offer lasting protection from pregnancy.
Frequently Asked Questions
Plan B One-Step may cause lower abdominal pain.
However, seek medical attention if pain persists for three to five weeks after taking it.
You may have an ectopic pregnancy, a pregnancy outside the uterus.
Plan B can cause menstrual irregularities due to its effect on delaying ovulation.
Food and Drug Administration.Plan B label.
Haeger KO, Lamme J, Cleland K.State of emergency contraception in the U.S., 2018.Contracept Reprod Med.
2018;3:20. doi:10.1186/s40834-018-0067-8
Plan B (Canada).Frequently asked questions.