The emergency contraceptive pill is sometimes called the “morning after pill”. There are two kinds of emergency contraceptive pill: Levonelle and ellaOne. Both work by preventing or delaying ovulation.
You can take Levonelle more than once in a menstrual cycle and it does not interfere with your regular method of contraception. It has to be taken within 72 hours (3 days) of sex.
ellaOne may prevent other types of hormonal contraception from working a week after use and is not recommended for use more than once in a menstrual cycle. It has to be taken within 120 hours (five days) of sex.
Neither protect against sexually transmitted infections (STIs). It is thought that ellaOne is more effective than Levonelle. You only take one tablet in both cases. Both are less effective than the copper IUD at preventing pregnancy. The sooner you take either pill, the more effective it will be.