The progestogen-only pill

The "traditional" progestogen-only pill (POP) prevents pregnancy by thickening the mucus in the cervix to stop sperm reaching an egg. The desogestrel progestogen-only pill can also stop ovulation. These pills contain the hormone progestogen, but don't contain oestrogen. They need to be taken daily.

If taken correctly, this pill is more than 99% effective. This means fewer than one woman in 100 who uses the progestogen-only pill as contraception will get pregnant in one year. But with "typical use" of the progestogen-only pill (the way it's taken by a lot of women in real life), it's only about 92% effective.

Call 0333 300 2100 for more information about sexual health and contraception in Merton, Richmond and Wandsworth.

Read more about the progestogen-only pill via the NHS Choices website