Emergency contraception from Nurx costs as little as $0 with insurance or $45 per pill without insurance.
The Plan B® (Levonorgestrel 1.5 mg) emergency contraceptive can delay ovulation for up to 5–7 days when taken before your luteinizing hormone (LH) surge begins. This gives sperm time to die in the reproductive tract before an egg is released. The exact duration depends on when in your cycle you take it, along with factors like body weight and metabolism.
- Spotting or irregular bleeding
- Breast tenderness
- Nausea or fatigue
- Mild abdominal cramps
- Keep a regular sleep routine
- Eat balanced meals and stay hydrated
- Manage stress with relaxation techniques
- Use condoms or another form of contraception until your next period
Does Plan B® delay ovulation or stop it?
Plan B® primarily works by delaying ovulation rather than completely stopping it. If you take Plan B® before your LH surge (the hormone signal that triggers ovulation), it postpones egg release temporarily. Once the medication leaves your system, your body resumes its normal cycle.
How does Plan B® delay ovulation?
Plan B® contains levonorgestrel, a synthetic hormone that interferes with your body’s natural ovulation signals. The medication works by suppressing the LH surge that normally triggers egg release from your ovary. This creates a temporary pause in your cycle, preventing sperm from meeting an egg.
How long does levonorgestrel delay ovulation?
Levonorgestrel can delay ovulation for approximately 5–7 days after taking the medication. This timeframe aligns with sperm survival time in the female reproductive tract (up to 5 days). The delay gives existing sperm time to die before your egg is released, preventing fertilization.
How many days does Plan B® delay ovulation?
Plan B® may delay ovulation, especially when taken before the luteinizing hormone (LH) surge. Some research suggests the delay can last up to about 5–7 days, though responses vary depending on timing in the cycle and individual factors. The sooner you take it after unprotected sex, the more likely it is to delay ovulation long enough to prevent fertilization.
Does Plan B® change up your ovulation cycle?
Yes, but only temporarily. Plan B® may cause your next period to occur up to a week early or late and may alter your menstrual flow. Most people return to their usual cycle pattern by the following month.
Temporary side effects may include:
What factors affect Plan B® delay?
Several factors influence how effectively Plan B® delays ovulation. Body weight plays a significant role, with reduced effectiveness in women with higher body weight or BMI. Timing matters too—taking Plan B® closer to ovulation reduces its ability to delay egg release. Other medications, particularly those affecting liver enzymes, can decrease levonorgestrel’s effectiveness.
How do I manage my cycle after Plan B®?
Track your cycle after taking Plan B®. Take note of when you took the pill and when your next period starts. Take a pregnancy test if your period is more than 7 days late.
To support recovery:
How to handle delayed ovulation after Plan B®
If you’re concerned about how long Plan B® delays ovulation or need guidance managing your cycle after emergency contraception, reaching out to a licensed provider can offer you the guidance and peace of mind you need.
Nurx offers emergency contraception options and ongoing birth control planning with the guidance you need to go along with it. Get the help you need delivered discreetly to your door with our convenient online consultations. With Nurx, taking control of your reproductive health is fast, straightforward, and fully within your control.
The information provided is not a substitute for professional medical advice, diagnosis, or treatment. You should not rely upon this content for medical advice. If you have any questions or concerns, please talk to a medical professional.
Levonorgestrel (generic Plan B® ) tablet 1.5 mg, intended to reduce the chance of pregnancy after unprotected sex, may cause side effects, including dizziness, abdominal pain, diarrhea, headache, fatigue, irregular menstruation, breast tenderness, nausea or spotting. If you would like to learn more about Levonorgestrel tablet 1.5 mg, please see product information here. Use as directed.
Individual results may vary.