Desogestrel

Key facts

• Desogestrel is a progestin used alone as a progestin-only contraceptive pill (sold as Cerazette) or combined with ethinyl estradiol in combined pills (such as Marvelon).
• Taken once daily at the same time; the progestin-only pill allows a 12-hour window for a missed dose before extra contraception is needed.
• Combined pills containing desogestrel carry a higher risk of blood clots, such as deep vein thrombosis and pulmonary embolism, than combined pills containing levonorgestrel; this added risk does not apply to the progestin-only pill.
• Seek urgent care for leg pain or swelling, sudden chest pain or breathlessness, or a sudden severe headache with vision changes or slurred speech.

What desogestrel treats

Desogestrel prevents pregnancy by suppressing ovulation. Combined pills, and some progestin-only regimens, are also used to make heavy or irregular periods lighter and more predictable. It is not effective against sexually transmitted infections and offers no protection against them.

How desogestrel works

Desogestrel mimics natural progesterone, signalling the brain to suppress the hormone surge that normally triggers ovulation. It also thickens cervical mucus, blocking sperm from reaching the uterus, and thins the uterine lining, making implantation less likely. In combined pills, ethinyl estradiol adds extra cycle control on top of this effect.

Before you take it

• Do not use it if you are or might be pregnant, or if you have a history of blood clots, certain liver tumors, current breast cancer, or unexplained vaginal bleeding.
• Combined pills should generally be avoided by smokers over 35, and by anyone with migraine with aura, uncontrolled high blood pressure, or a personal or family history of blood clots.
• Some antibiotics, anticonvulsants, and St John's wort can reduce effectiveness; use backup contraception if you start one of these medicines.

Side effects

Common effects include nausea, headache, breast tenderness, irregular spotting between periods, and mood changes.

Stop and seek urgent medical care for any of these:

• Leg swelling or pain.
• Sudden chest pain or breathlessness.
• Sudden severe headache, vision changes, or slurred speech.
• Yellowing of the skin or eyes.

Safety essentials

• Know the blood clot warning signs (a painful, swollen leg, breathlessness, chest pain, or a sudden severe headache) and seek emergency care immediately if they appear; the risk is highest in the first year of combined-pill use and in smokers over 35.
• Vomiting or severe diarrhea within a few hours of a dose can reduce absorption; use backup contraception as directed.
• If you miss a pill, follow the specific missed-pill instructions for your product; the rules differ between the progestin-only and combined versions.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.