The progestogen-only pill (POP) contains a progestogen hormone which is similar to the natural progesterone women produce in their ovaries.
POPs contain different types of progestogens. POPs containing desogestrel will be named specifically where relevant on this page. If you are not sure what type of progestogen is in your POP, check the patient information leaflet inside your pack or ask your doctor or nurse. The POP works in a number of ways:
the main action of desogestrel POPs is to stop your ovaries releasing an egg (ovulation)
all POPs work by thickening the mucus from your cervix. This makes it difficult for sperm to move through it and reach an egg
all POPs make the lining of your uterus (womb) thinner, so it is less likely to accept a fertilised egg
If taken according to instructions, the POP is over 99% effective. This means that less than one woman in 100 will get pregnant in a year.