Plan B One-Step

Plan B is an emergency contraceptive used to prevent pregnancy after unprotected sex. It is available without a prescription to all women (including those under 18 years of age).

Plan B One-Step Overview

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Plan B One-Step is an emergency contraceptive used to prevent pregnancy after unprotected sex or birth control failure. Plan B contains the hormone levonorgestrel. Levonorgestrel belongs to a group of drugs called progestins. It works by preventing the release of an egg from the ovary or preventing fertilization of the egg by sperm (male reproductive cells). It also may work by changing the lining of the uterus (womb) to prevent development of a pregnancy. 

Plan B One-Step comes as one tablet and should be taken as soon as possible, within 72 hours (3 days), after having unprotected sex.

Common side effects of Plan B One-Step include changes in your period, nausea, and tiredness.

Plan B One-Step causes tiredness and dizziness. Do no drive or operate heavy machinery until you know how Plan B One-Step affects you.

 

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Uses of Plan B One-Step

Plan B One-Step is emergency contraception that helps prevent pregnancy after birth control failure or unprotected sex. It is available without a prescription to all women (including those under 18 years of age).

  • It is a backup method of preventing pregnancy and should not be used as regular birth control because it’s not as effective as regular birth control.
  • Plan B One-Step will not work if you are already pregnant and will not affect an existing pregnancy.
  • Plan B One-Step will not protect you from HIV infection (the virus that causes AIDS) and other sexually transmitted diseases (STDs).

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Plan B One-Step Drug Class

Plan B One-Step is part of the drug class:

Side Effects of Plan B One-Step

Serious side effects have been reported with Plan B One-Step. See the “Plan B One-Step Precautions” section.

Common side effects of Plan B One-Step include:

  • changes in your period such as a period that is heavier or lighter or a period that is early or late
  • nausea
  • lower stomach (abdominal) pain
  • tiredness
  • headache
  • dizziness
  • breast tenderness

Plan B One-Step causes tiredness and dizziness. Do no drive or operate heavy machinery until you know how Plan B One-Step affects you.

This is not a complete list of Plan B One-Step side effects. Ask your doctor or pharmacist for more information.

Tell your doctor if you have any side effect that bothers you or that does not go away.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Plan B One-Step Interactions

Tell your doctor or pharmacist about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Drugs that may affect Plan B One-Step include:

  • medications that increase the activity of the enzyme CYP3A4 such as carbamazepine (Tegretol, Equetro, Carbatrol), phenobarbital, phenytoin (Dilantin), rifampin (Rifadin), and St John's wort

This is not a complete list of Plan B One-Step drug interactions. Ask your doctor or pharmacist for more information.

 

 

Plan B One-Step Precautions

Serious side effects have been reported with Plan B One-Step including the following:

  • severe lower stomach (abdominal) pain. If you have severe lower stomach (abdominal) pain, you may have an ectopic pregnancy, and should get immediate medical attention. An ectopic pregnancy is a pregnancy in which the fertilized egg implants outside the uterus.

Plan B One-Step should not be used:

  • as a regular birth control method, because it’s not as effective as regular birth control.
  • if you are already pregnant, because it will not work.
  • if you are allergic to levonorgestrel or any other ingredients in Plan B One-Step.

Plan B One-Step Food Interactions

Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of Plan B One-Step, there are no specific foods that you must exclude from your diet when receiving this medication.

People who have trouble digesting the milk sugar lactose, should use caution when taking Plan B One-Step since it contains lactose. 

Inform MD

Before taking Plan B One-Step, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

  • are allergic to Plan B One-Step or to any of its ingredients
  • are pregnant
  • are breastfeeding
  • are using Plan B One-Step as a form of regular birth control

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.

Plan B One-Step and Pregnancy

Plan B One-Step will not work if you are already pregnant and will not affect an existing pregnancy.

If your period is delayed beyond 1 week after taking Plan B One-Step, it is possible you may be pregnant. You should get a pregnancy test and follow up with your healthcare professional.

Plan B One-Step and Lactation

Tell your doctor if you are breastfeeding or plan to breastfeed.

Progestins (levonorgestrel is a progrestin) have been detected in human breast milk. Because of the possibility for adverse reactions in nursing infants from Plan B One-Step, a choice should be made whether to stop nursing or to stop use of this medication. The importance of the drug to the mother should be considered. 

Plan B One-Step Usage

  • Plan B One-Step comes as one tablet that is taken by mouth. 
  • You have 72 hours (3 days) to try to prevent pregnancy after birth control failure or unprotected sex. The sooner you take Plan B One-Step, the better it works.
  • If you vomit within 2 hours of taking the medication, call a healthcare professional to find out if you should repeat the dose.
  • You will know Plan B One-Step has been effective when you get your next period, which should come at the expected time, or within a week of the expected time. If your period is delayed beyond 1 week, it is possible you may be pregnant. You should get a pregnancy test and follow up with your healthcare professional.

 

Plan B One-Step Dosage

Plan B One-Step is a single pill you take by mouth.

It must be taken as soon as possible, within 72 hours (3 days), after unprotected sex or birth control failure to help prevent pregnancy. The sooner you take it, the better it works.

Plan B One-Step Overdose

If you take too much Plan B One-Step, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

 

Other Requirements

  • Store Plan B One-Step at room temperature, 68º to 77ºF (20º to 25ºC). 
  • Keep this and all medications out of the reach of children.