What are the possible side effects of Ella (ulipristal acetate) emergency contraception, including rare ones?

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Side Effects of Ella (Ulipristal Acetate) Emergency Contraception

The most common side effects of Ella (ulipristal acetate) emergency contraception include headache (18-19%), nausea (12-13%), abdominal pain (8-15%), menstrual pain (7-13%), fatigue (6%), and dizziness (5%). 1

Common Side Effects

Ella's FDA label clearly documents the most frequently reported adverse reactions in clinical trials:

  • Headache (18-19% of users)
  • Nausea (12-13% of users)
  • Abdominal and upper abdominal pain (8-15% of users)
  • Dysmenorrhea (menstrual pain) (7-13% of users)
  • Fatigue (6% of users)
  • Dizziness (5% of users) 1

Menstrual Effects

Ella can affect your menstrual cycle in the following ways:

  • Delayed menses: Your next period may be delayed by approximately 2-3 days after taking Ella 1
  • Changes in menstrual cycle: Some women may experience their next period earlier or later than expected 1
  • If your period is more than a week late after taking Ella, you should take a pregnancy test and follow up with your healthcare provider 1

Rare but Serious Side Effects

While uncommon, there are some rare but potentially serious side effects to be aware of:

  • Ectopic pregnancy: If you experience severe lower abdominal pain about 3-5 weeks after taking Ella, you may have an ectopic pregnancy (pregnancy outside the womb), which requires immediate medical attention 1

Post-Marketing Reported Side Effects

The following adverse reactions have been identified during post-approval use of Ella:

  • Skin reactions:
    • Acne
    • Hypersensitivity reactions including rash, urticaria (hives), pruritus (itching), and angioedema (swelling) 1

Special Considerations

  • Breastfeeding: A small amount of the hormones in Ella may pass into breast milk. Discuss with your healthcare provider about the best birth control options while breastfeeding 1

  • Drug interactions: Certain medications may make Ella less effective, including:

    • Hormonal birth control methods (pills, implants, IUDs, patches)
    • St. John's Wort
    • Certain medications like bosentan, griseofulvin, phenytoin, topiramate, oxcarbazepine, carbamazepine, barbiturates, rifampin, and felbamate 1

Important Precautions After Taking Ella

  1. Use a reliable barrier birth control method (such as condom with spermicide) until your next menstrual period 1

  2. Do not use levonorgestrel emergency contraceptive pills within 5 days after taking Ella 1

  3. Wait 5 days to start or resume hormonal birth control methods (such as the pill, patch, or vaginal ring) 1

  4. If you vomit within 3 hours of taking Ella, contact your healthcare provider as you may need another dose 1

Efficacy Considerations

While not a side effect, it's worth noting that ulipristal acetate (Ella) has been shown to be more effective than levonorgestrel (Plan B) emergency contraception, especially when taken later in the 120-hour window after unprotected intercourse 2. This is particularly important for women with higher BMI, as Ella maintains better efficacy in this population compared to levonorgestrel-based emergency contraception 2.

References

2
Guideline

Contraception Guidelines

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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