Question: how effective is the morning after pill if taken within 12 hours?
Answer: Levonorgestrel is most effective when taken within 12 hours of unprotected sex, although it can be effective for up to 72 hours after sex. You should bear in mind, however, that this effectiveness decreases over time. Levonorgestrel is thought to prevent: up to 95% of pregnancies if taken within 24 hours.