The Core Function of the Contingency Pill
The term "contingency pill" refers to emergency contraception pills (ECPs) that are used as a backup plan to prevent pregnancy following unprotected sex. The main way these pills work is by interfering with a woman's hormonal cycle to prevent or delay ovulation—the release of an egg from the ovary. By delaying ovulation, the pill ensures that no egg is available for fertilization by sperm, which can live in the female reproductive tract for several days. Without a released egg, pregnancy cannot occur.
It is important to understand that ECPs are a form of contraception, not abortion. They will not terminate an existing pregnancy and are not effective once the fertilized egg has already implanted in the uterine wall. Emergency contraception is a safe and effective option for preventing pregnancy, but it is not intended for regular use and is less effective than long-term birth control methods.
Types of Emergency Contraception Pills
There are two main types of emergency contraception pills available, each with a different active ingredient and effective time window. Your choice may depend on how much time has passed since unprotected sex, your body weight, and your access to a prescription.
Levonorgestrel (Plan B One-Step and generics)
Pills containing levonorgestrel, such as Plan B One-Step, Take Action, and other generic brands, are available over-the-counter in most drugstores and pharmacies, with no age or gender restrictions.
- How it works: Primarily delays or prevents ovulation.
- Timing: Most effective when taken within 72 hours (3 days) of unprotected sex, but can be taken up to 120 hours (5 days). Effectiveness decreases over time.
- Weight limitations: May be less effective for individuals weighing over 165 pounds.
Ulipristal Acetate (ella)
Ella is a prescription-only ECP containing ulipristal acetate, which is a progesterone receptor modulator.
- How it works: Prevents or delays ovulation, even if taken closer to the time of ovulation than levonorgestrel.
- Timing: Can be taken up to 120 hours (5 days) after unprotected sex with no decrease in effectiveness throughout the window.
- Weight limitations: More effective for individuals with a higher body mass index (BMI) than levonorgestrel, but may be less effective for those weighing over 195 pounds.
Comparison of EC Pills
| Feature | Levonorgestrel (e.g., Plan B) | Ulipristal Acetate (ella) |
|---|---|---|
| Active Ingredient | Levonorgestrel | Ulipristal Acetate |
| Accessibility | Over-the-counter (OTC) without a prescription | Prescription required |
| Effective Window | Most effective within 72 hours, up to 120 hours | Up to 120 hours (5 days) |
| Effectiveness with Time | Decreases significantly the longer you wait | Remains highly effective throughout the 5-day window |
| Weight Limitation | May be less effective for people over 165 pounds | Less effective for people over 195 pounds |
| Ovulation Timing | Less effective if taken closer to ovulation | More effective than Plan B closer to ovulation |
| Breastfeeding | Considered safe | Requires discarding milk for 24 hours after use |
When to Use the Contingency Pill
The contingency pill is a backup plan, not a regular form of birth control. It is designed for situations where contraception was not used or failed unexpectedly. These include:
- A condom breaking or slipping off during intercourse.
- Missing multiple doses of a regular birth control pill pack.
- Forgetting or being late for a scheduled contraceptive injection.
- Experiencing a miscalculation of fertile days during fertility awareness-based methods.
- Not using any contraception during intercourse.
What to Expect: Side Effects and Next Steps
After taking a contingency pill, some women may experience temporary side effects. These are typically mild and resolve within a few days.
Common side effects include:
- Nausea, with or without vomiting.
- Headache.
- Dizziness.
- Breast tenderness.
- Abdominal pain or cramps.
- Changes to your menstrual cycle, such as your next period being earlier, later, lighter, or heavier.
If vomiting occurs within a few hours of taking the pill, consult a healthcare professional, as you may need to take another dose. Your next menstrual period may be delayed, but if it is more than a week late, you should take a pregnancy test. It is important to resume or start a regular form of birth control, as the contingency pill does not offer ongoing protection.
Conclusion
The contingency pill is a vital and safe tool for preventing unintended pregnancy in emergencies. By understanding what the contingency pill does, the differences between the available types, and the importance of timing, individuals can make informed decisions about their reproductive health. While it provides a crucial safety net, it is most effective when used promptly after unprotected sex and should not replace a regular birth control method. For ongoing contraception, other options are more effective and should be discussed with a healthcare provider. Resources like Planned Parenthood can offer further guidance and information on all birth control options.
