July 25, 2016
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Plan B

"Today, the U.S. Food and Drug Administration announced it has approved the use of Plan B One-Step (levonorgestrel) as a nonprescription product for all women of child-bearing potential. This action complies with the April 5, 2013 order of the Uni"...


Plan B

Side Effects


The most common adverse events in the clinical trial for women receiving Plan B® (levonorgestrel) included nausea (23%), abdominal pain (18%), fatigue (17%), headache (17%), and menstrual changes. The table below shows those adverse events that occurred in ≥5% of Plan B® (levonorgestrel) users.

Table 3
Adverse Events in ≥ to 5% of Women, by % Frequency

Most Common
Adverse Events
Plan B®
N = 977 (%)
Nausea 23.1
Abdominal Pain 17.6
Fatigue 16.9
Headache 16.8
Heavier Menstrual Bleeding 13.8
Lighter Menstrual Bleeding 12.5
Dizziness 11.2
Breast Tenderness 10.7
Other complaints 9.7
Vomiting 5.6
Diarrhea 5.0

Plan B® (levonorgestrel) demonstrated a superior safety profile over the Yuzpe regimen for the following adverse events:

  • Nausea: Occurred in 23% of women taking Plan B® (levonorgestrel) (compared to 50% with Yuzpe)
  • Vomiting: Occurred in 6% of women taking Plan B® (levonorgestrel) (compared to 19% with Yuzpe)


There is no information about dependence associated with the use of Plan B® (levonorgestrel) .

Read the Plan B (levonorgestrel) Side Effects Center for a complete guide to possible side effects


Theoretically, the effectiveness of low-dose progestin-only pills is reduced by hepatic enzyme-inducing drugs such as the anticonvulsants phenytoin, carbamazepine, and barbiturates, and the antituberculosis drug rifampin. No significant interaction has been found with broad-spectrum antibiotics. It is not known whether the efficacy of Plan B® (levonorgestrel) would be affected by these or any other medications.

Read the Plan B Drug Interactions Center for a complete guide to possible interactions

This monograph has been modified to include the generic and brand name in many instances.

Last reviewed on RxList: 5/24/2007

Side Effects

Plan B - User Reviews

Plan B User Reviews

Now you can gain knowledge and insight about a drug treatment with Patient Discussions.

Here is a collection of user reviews for the medication Plan B sorted by most helpful. Patient Discussions FAQs

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.

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