The Emergency contraceptive acts by preventing or delaying ovulation. If a woman has had sex more than once in one night (or one day), she does not need to take more than one course of EC following those acts of intercourse.
Theoretically speaking the action of the Emergency contraceptive pill covers for around 72 hours, the efficacy however goes down with an increase in the time gap between the act of coitus and time of taking the pill. The greatest efficacy of the pill is if this interval is 24 hours during which the pill is 95% effective.The efficacy decreases to 85% if taken within 25–48 hours and to 58% if taken within 49–72 hours.
The emergency pill was not designed to be a regular kind of contraceptive and can be disruptive for your menstrual cycle. It also does not protect you against the possibility of sexually transmitted infections. It is advised that you use a more reliable method of contraception in the future for better protection.
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.