MODEL RELEASED. Contraceptive pills. 20-year-old woman preparing to take oral contraceptive pills. These contain synthetic versions of one or both of the female sex hormones responsible for ovulation, the production of the female reproductive cell. The pill acts to suppress ovulation and effect changes in the reproductive organs to impede fertilisation and pregnancy. These pills are taken daily for three weeks, with a one week break for menstruation. The days marked on the foil remind one when the next pill is due to be taken. These are Mercilon contraceptive pills, made by Organon Laboratories. They contain ethinylestradiol (an oestrogen) and desogestrol (a progestogen).