Can I take Plan B if I'm overweight?

Levonorgestrel, the active ingredient of Plan B, may be less effective in people with a higher body mass index (BMI of 30 or higher). However, Plan B is generally considered very effective for individuals under 165 lbs. While Plan B for overweight individuals may be less effective, prescription Ulipristal (ella) does not have a BMI limit and is shown to be effective in individuals up to 195 lbs. Taking Ella if overweight is not only more effective at preventing pregnancy, it may be taken up to 5 days following contraceptive failure.