The 72-Hour Window: Understanding Plan B (Levonorgestrel)
Plan B One-Step and its generic versions contain levonorgestrel, a synthetic progestin hormone. This medication works primarily by delaying or preventing ovulation, meaning it stops the release of an egg from the ovary. For this mechanism to be effective, it must be taken before the luteinizing hormone (LH) surge begins, which triggers ovulation. The manufacturer-recommended window for maximum effectiveness is within 72 hours (3 days) of unprotected sex. While some studies show limited effectiveness up to 120 hours, the efficacy drops significantly after the first 72 hours. Additionally, its effectiveness may be reduced in individuals who weigh more than 165 pounds.
The Extended 120-Hour Window: Ella (Ulipristal Acetate)
For those who need to act beyond the 72-hour mark, the prescription pill Ella is a crucial alternative. Ella contains ulipristal acetate, a different type of emergency contraceptive. It is effective for up to 120 hours (5 days) after unprotected sex. Unlike Plan B, Ella is a selective progesterone receptor modulator, and it can delay or prevent ovulation even after the LH surge has started. This unique mechanism is why it maintains a more consistent efficacy over the five-day window compared to levonorgestrel. As a prescription-only medication, individuals must obtain it from a healthcare provider or through a telehealth service.
The Most Effective Option: The Copper IUD (ParaGard)
The most effective form of emergency contraception available is the copper intrauterine device (IUD), known by the brand name ParaGard. A healthcare provider must insert this small, T-shaped device into the uterus within 120 hours (5 days) of unprotected sex to be effective. The copper IUD works by releasing copper ions that are toxic to sperm, preventing fertilization. It also creates a sterile inflammatory response in the uterus that interferes with implantation if fertilization has already occurred. A significant benefit of the copper IUD is that once inserted, it provides highly effective, long-term birth control for up to 10-12 years. Unlike the pills, its effectiveness is not affected by body weight.
Comparing Your Emergency Contraception Options
| Feature | Plan B (Levonorgestrel) | Ella (Ulipristal Acetate) | Copper IUD (ParaGard) |
|---|---|---|---|
| Effective Window | Up to 72 hours (3 days); efficacy declines over time. | Up to 120 hours (5 days); efficacy remains high throughout. | Up to 120 hours (5 days). |
| Availability | Over-the-counter at most drugstores; no age restriction. | Prescription only; can be obtained from a healthcare provider or via telehealth. | Requires insertion by a healthcare provider at a clinic. |
| Prescription Required? | No. | Yes. | Yes (requires a procedure). |
| Relative Effectiveness | Effective, but less so than Ella, especially after 72 hours. | More effective than Plan B, especially in the 72–120 hour window. | The most effective emergency contraception available. |
| Weight Considerations | May be less effective for individuals over 165 lbs. | May be less effective for individuals over 195 lbs. | No known reduction in effectiveness due to weight. |
| Mechanism of Action | Primarily delays or inhibits ovulation. | Delays or inhibits ovulation, even during the LH surge. | Interferes with sperm movement and prevents fertilization/implantation. |
| Long-term Contraception? | No; does not provide future protection. | No; does not provide future protection. | Yes; can be left in place for up to 10-12 years. |
What to do if you need emergency contraception after 72 hours
If more than 72 hours have passed since unprotected sex, seeking emergency contraception quickly is still crucial. Your best options are Ella or a copper IUD. Here are the recommended steps:
- Contact a healthcare provider immediately. Explain your situation and timeline. A provider can write a prescription for Ella or help you schedule an appointment for a copper IUD insertion.
- Use a telehealth service. Online platforms can often provide a consultation and prescription for Ella in a short amount of time.
- Call a local clinic or Planned Parenthood. These clinics often have same-day or walk-in appointments for both Ella prescriptions and IUD insertion.
- Prioritize the copper IUD if possible. Given its high efficacy and long-term benefits, the copper IUD is the gold standard for emergency contraception and ongoing birth control.
- Act as soon as possible, regardless of the method. While Ella and the IUD have a 120-hour window, all forms of emergency contraception are more effective the sooner they are used.
Conclusion
To answer the question, is there a Plan B pill that works longer than 72 hours?, the answer is no, but an alternative pill called Ella does. For those who have passed the 72-hour mark, Ella, available by prescription, offers effective protection for up to 120 hours. The most effective method, however, is the copper IUD, which is also effective for up to 120 hours and provides reliable, long-term contraception. Acting quickly and speaking with a healthcare provider will help determine the best and most accessible option for your specific circumstances.
For more comprehensive information on emergency contraception, you can refer to the resources from Planned Parenthood.
