Can Plan B (levonorgestrel) cause prolonged menstrual bleeding?

Plan B Can Cause Prolonged Bleeding

Yes, Plan B (levonorgestrel) can cause prolonged menstrual bleeding as a side effect, though this is generally temporary and not harmful to health. Menstrual disturbances are common after using emergency contraception containing levonorgestrel.

Bleeding Pattern Changes After Plan B

Plan B affects menstrual patterns in several ways:

• Timing changes: Taking Plan B can shorten the menstrual cycle, particularly when taken early in the cycle 1
• Duration changes: The first menstrual period after Plan B may be longer than usual, especially when taken later in the cycle 1
• Bleeding patterns: Some women experience:
  • Normal bleeding (57% of women) 2
  • Intermenstrual bleeding or spotting 2
  • Premenstrual bleeding or spotting 2
  • Menorrhagia (heavy bleeding) 2

Prevalence and Expectations

Research shows that menstrual disturbances are common but generally well-tolerated:

• In a study of 544 women using a single 1.5mg dose of levonorgestrel, 43% experienced some form of abnormal bleeding 2
• Early or timely return of menses occurred in 69% of women, while 21% experienced delayed menses (more than a week late) 2
• Intermenstrual bleeding occurred in only about 5% of women in the first cycle after treatment 1

Management of Prolonged Bleeding

If prolonged bleeding occurs after Plan B use and is concerning:

1. Rule out other causes: Consider potential underlying gynecological problems such as:

   • Pregnancy (including ectopic pregnancy)
   • STDs
   • Pathologic uterine conditions (polyps, fibroids)
   • Medication interactions 3

2. Treatment options if bleeding is bothersome:

   • NSAIDs for short-term treatment (5-7 days) 3
   • Hormonal treatment with low-dose combined oral contraceptives for short-term treatment (10-20 days) if medically eligible 3

Important Considerations

• Timeframe: Bleeding irregularities after Plan B are typically temporary and resolve with the next menstrual cycle
• Warning signs: Severe abdominal pain could indicate ectopic pregnancy and requires immediate medical attention 4
• Regular contraception: Plan B should not be used as regular contraception as it's not as effective as other methods and can cause menstrual disturbances 4

When to Seek Medical Care

Consult a healthcare provider if:

• Bleeding is extremely heavy or prolonged beyond one cycle
• Severe abdominal pain occurs
• Menstrual period is more than a week late (possible pregnancy) 4
• Bleeding irregularities persist and are unacceptable 3

Remember that while menstrual changes after Plan B use are common, they are generally temporary and not harmful to health. The medication's effectiveness in preventing pregnancy (preventing about 80% of pregnancies when taken within 72 hours of unprotected intercourse) outweighs these temporary side effects 5.