From the Guidelines
Plan B (levonorgestrel) emergency contraception is not known to cause ovarian cysts or uterine fibroids. The primary mechanism of action of levonorgestrel is to prevent or delay ovulation, and there is no established causal relationship between its use and the development of ovarian cysts or uterine fibroids 1. While some hormonal contraceptives used long-term may influence ovarian cyst formation, Plan B is a single-dose emergency contraceptive rather than a regular hormonal treatment. Temporary hormonal fluctuations after taking Plan B might cause menstrual irregularities for one cycle, but these effects are transient. Ovarian cysts and uterine fibroids typically develop due to other factors such as genetics, hormonal imbalances over time, or age-related changes. According to the U.S. Medical Eligibility Criteria for Contraceptive Use, 2010, there are specific recommendations for women with certain medical conditions, including ovarian cancer and uterine fibroids, but these do not imply a causal relationship between levonorgestrel use and the development of these conditions 1. If you experience persistent pelvic pain, unusual bleeding, or other concerning symptoms after taking Plan B, you should consult with a healthcare provider, as these symptoms are likely unrelated to the emergency contraceptive and may require medical evaluation. Some key points to consider include:
- The difference between emergency contraception and regular hormonal treatment
- The primary mechanism of action of levonorgestrel
- The lack of established causal relationship between levonorgestrel use and ovarian cysts or uterine fibroids
- The importance of consulting a healthcare provider for persistent or concerning symptoms.
From the Research
Plan B and Ovarian Cysts or Uterine Fibroids
- The relationship between Plan B (levonorgestrel) and the development of ovarian cysts or uterine fibroids is complex and has been studied in various contexts.
- A study from 2002 2 found that the use of a levonorgestrel-releasing intrauterine system (LNG-IUS) was associated with the development of ovarian cysts, but these cysts were symptomless and showed a high rate of spontaneous resolution.
- The same study found that LNG-IUS did not affect the size of the uterus or uterine fibroids, but decreased the thickness of the endometrium.
- Another study from 2017 3 discussed the use of LNG-IUS in the treatment of symptomatic uterine fibroids, suggesting that it may be an effective and safe treatment option for premenopausal women.
- A 2023 case report 4 presented a patient with simultaneous uterine fibroids and ovarian cysts, highlighting the complexity of managing these conditions when they coexist.
- A 2002 pilot study 5 evaluated the effect of a novel "frameless" intrauterine levonorgestrel-releasing drug delivery system on menstrual blood loss in women with uterine fibroids, finding that it significantly reduced bleeding in most patients.
Key Findings
- Levonorgestrel, the active ingredient in Plan B, may be associated with the development of ovarian cysts when used in an intrauterine system 2.
- LNG-IUS may be an effective treatment option for symptomatic uterine fibroids in premenopausal women 3.
- The coexistence of uterine fibroids and ovarian cysts can present a complex management scenario 4.
- A frameless intrauterine levonorgestrel-releasing system can significantly reduce menstrual blood loss in women with uterine fibroids 5.
Studies on Levonorgestrel and Fibroids
- A 2012 review 6 discussed the medical management of symptomatic non-submucosal uterine fibroid tumors, including the use of progestogens and levonorgestrel-releasing intrauterine devices.
- The review highlighted the importance of considering the patient's individual circumstances and preferences when selecting a treatment option for uterine fibroids.