Medically reviewed by Alan Lucks | MD, Alan Lucks MDPC Private Practice - New York on January 23rd, 2026.
Plan B is most effective when taken within 24 hours of unprotected intercourse
Effectiveness decreases over time, dropping to 58% by 72 hours
Safe for most women, with few significant side effects
Consider consulting a healthcare provider for personalized advice
Emergency contraception provides a critical backup option for preventing unintended pregnancy. Plan B One-Step offers a reliable method for women seeking to reduce pregnancy risk after unprotected sexual activity or contraceptive failure. Understanding the nuanced details of when and how to use this medication can make a significant difference in its effectiveness.
Several key scenarios might necessitate the use of Plan B. Unprotected sexual intercourse represents the most common situation, which can occur due to spontaneous intimacy or unexpected circumstances. Birth control interactions can also create scenarios where emergency contraception becomes necessary, such as when medications interfere with regular birth control effectiveness.
Contraceptive failures provide another critical reason for considering emergency contraception. This includes situations like:
Condom breakage or slippage
Missed birth control pills
Medication interactions reducing contraceptive protection
Sexual assault survivors seeking preventive care
Timing represents the most crucial element in Plan B's effectiveness. The medication works most optimally when taken quickly after unprotected intercourse:
Timing |
Effectiveness Rate |
|---|---|
Within 24 hours |
95% |
24-48 hours |
85% |
48-72 hours |
58% |
Some research suggests limited protection may exist up to 120 hours after intercourse, though effectiveness significantly diminishes. Women should prioritize taking Plan B as soon as possible to maximize pregnancy prevention.
Before taking Plan B, women should evaluate several important health factors. Side effects of birth control can vary, and emergency contraception is no different. Body weight may impact effectiveness, with reduced efficacy potentially occurring in women weighing over 165 pounds.
Key considerations include:
Current pregnancy status
Liver health
Medication interactions
Breastfeeding status
Most women experience minimal side effects from Plan B. Temporary changes might include:
Slight menstrual cycle disruption
Mild cramping
Potential nausea
Slight breast tenderness
Emergency contraception provides an important option for preventing unintended pregnancy. While effective, it should not replace regular birth control methods. Need personalized guidance? Ready to meet your AI doctor? Get started with Doctronic today.
Emergency contraception provides a critical backup option for preventing unintended pregnancy. Plan B One-Step offers a reliable method for women seeking to reduce pregnancy [...]
Read More
