The morning-after pill, like Julie, is 89% effective when taken within 72 hours (or 3 days) after unprotected sex. The golden rule is the sooner you take it, the better it will work.
One thing to note: Weight does impact the effectiveness of the morning-after pill. A few studies have shown that the effectiveness of the morning-after pill does decrease in people who weigh more than 165 pounds or have a body mass index (BMI) over 25. If your BMI is over 25, Julie may not be the best option for you, but there are other options if you have access to a medical provider. Ella® is another type of emergency contraception pill that works more effectively for women with a BMI under 30. Like Julie, it’s a one-time pill but it does require a prescription from your provider. Copper and hormonal IUDs are the most effective form of emergency contraceptive and are not affected by weight at all. However, they do need to be inserted by a healthcare professional up to 5 days after having unprotected sex.
Learn more about how weight impacts Julie here.