Copper releasing intra uterine device is Cu-T. It prevents pregnancy in the following ways :
By increasing phagocytosis of sperms within the uterus.
By supressing sperm motility and thereby the fertilizing ability.
By making the uterus unsuitable for implantation.
Saheli is an example of oral contraceptive that contains a non-steroidal component called 'Centchroman' it is a once-a-week pill.
Other oral contraceptive pills have to be taken daily for a period of 21 days, starting within the first five days of mentrual cycle.