>plan B has a weight limit of 155 lbs. Above or below 155 lbs? So I went an had a search. It doesn't have a weight limit, but … >Some studies suggest that Plan B may be less effective for people who weigh more than 155 pounds (70.3 kilograms). Other studies suggest that Plan B may be less effective for people who weigh over 176 pounds (80 kilograms) or have a body mass index (BMI) at or above 30. So it's like alcohol? The bigger you are the more it takes to have an impact?