Plan B One-Step

Medical Editor: John P. Cunha, DO, FACOEP Last updated on RxList: 5/31/2022

Drug Summary

What Is Plan B One-Step?

Plan B One-Step (levonorgestrel tablet) is a progestin-only emergency contraceptive used for prevention of pregnancy following unprotected intercourse or a known or suspected contraceptive failure. People sometimes call Plan B One-Step the "morning after pill." Plan B One-Step does not protect against sexually transmitted diseases.

What Are Side Effects of Plan B One-Step?

Common side effects of Plan B One-Step include

  • nausea,
  • vomiting,
  • stomach or abdominal pain,
  • diarrhea,
  • dizziness,
  • tired feeling,
  • breast pain or tenderness,
  • changes in your menstrual periods, or
  • headache.

Dosage for Plan B One-Step

The recommended dosage of Plan B One-Step is one pill as soon as possible within 72 hours after unprotected intercourse or a known or suspected contraceptive failure.

What Drugs, Substances, or Supplements Interact with Plan B One-Step?

Plan B One-Step may interact with rifampin, barbiturates, or seizure medicines. Tell your doctor all medications and supplements you use. It can be used at any time during the menstrual cycle. If vomiting occurs within two hours of taking the tablet, consideration should be given to repeating the dose. Plan B One-Step should not be taken as regular birth control.

Plan B One-Step During Pregnancy or Breastfeeding

Do not take Plan B One-Step if you are already pregnant. Consult your doctor before breastfeeding.

Additional Information

Our Plan B One-Step (levonorgestrel tablet) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

Drug Description


Drug Facts

Active ingredient

Levonorgestrel 1.5mg Tablet

Side Effects & Drug Interactions


No information provided. Please refer to the WARNINGS section.


No information provided.

Warnings & Precautions


Allergy alert: Do not use if you have ever had an allergic reaction to Levonorgestrel

Sexually transmitted diseases (STDs ) alert: This product does not protect against HIV/AIDS or other STDs

Do not use

  • if you are already pregnant (because it will not work)
  • for regular birth control

When using this product you may have

  • menstrual changes
  • nausea
  • lower stomach (abdominal) pain
  • tiredness
  • headache
  • dizziness
  • breast pain
  • vomiting


No information provided.

Overdose & Contraindications


In case of overdose, get medical help or contact a Poison Control center right away.


No information provided

Clinical Pharmacology


No information provided.

Medication Guide


No information provided. Please refer to the WARNINGS section.

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Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.