Desogestrel

How it works

It acts primarily by inhibiting ovulation, supplemented by thickening of cervical mucus to impede sperm penetration and changes to the endometrium.

Prescribing in practice

• Unlike traditional progestogen-only pills, desogestrel reliably suppresses ovulation, but a missed pill beyond the permitted window still requires additional contraceptive precautions and consideration of emergency contraception.
• It can be used in many women in whom oestrogen is contraindicated, including during breastfeeding.
• Irregular or unpredictable bleeding is the most common reason for discontinuation and should be discussed before starting.

Monitoring

No specific laboratory monitoring is required; assess blood pressure and review contraceptive needs and any new bleeding pattern at follow-up.

Counselling the patient

• Take one tablet at the same time each day without a break between packs.
• If a pill is taken late beyond the allowed window, use additional precautions such as condoms as advised.
• Irregular bleeding or spotting is common, especially in the early months.

Evidence & guidelines

Desogestrel-only contraception is recommended within UK guidance as an effective oestrogen-free option, including for breastfeeding women.