Female Birth Control Pills
The Pill is a tablet containing two female hormones – an oestrogen and a progestogen. This is why it's often called the combined Pill.
Various oestrogens and progestogens are used in the many different types of Pill that are available.
There are currently 28 brands on the market in Britain. Six new ones have recently been introduced, and one of these is being marketed on the basis of its ability to shorten periods. However, this is actually a welcome property of nearly all combined Pills.
The two hormones stop you from ovulating (producing an egg) each month. And if you don't ovulate, you won't get pregnant.
In addition, the hormones thicken the secretions round your cervix, making it more difficult for sperm to get through. Also, they make the lining of your womb thinner, so that it’s less receptive to an egg.