What desogestrel is
Desogestrel is a progestogen, a laboratory-made relative of the hormone progesterone. The liver converts it into etonogestrel, the form that actually acts on the body. It was developed to do that job with very little male-hormone-like effect, which is why it is grouped as a third-generation progestogen. Pills containing it are paired with ethinylestradiol, and the two prevent pregnancy mainly by stopping ovulation, with thickened mucus at the cervix as a second barrier. A pill with desogestrel alone exists too, but it is a different medicine; here desogestrel is sold only in the combined form.
The three listings
All three are tablets that pair desogestrel with ethinyl estradiol:
On paper the only difference is the oestrogen amount, 0.03mg or 0.02mg. Each page shows its own pack sizes.
How desogestrel shifts the risk picture
Pills with desogestrel carry a slightly higher risk of venous blood clots than the older levonorgestrel pills. A venous clot forms in a leg vein and can travel to the lungs. The absolute risk stays small, and it climbs with smoking, age over 35, obesity, long spells of immobility and a family history of clots. Stroke and heart attack are rarer, with similar risk factors, and migraine with aura rules combined pills out. Sudden chest pain or breathlessness, a swollen painful leg, or a sudden loss of vision calls for urgent treatment.
Everyday effects and interactions
The common complaints are nausea, tender breasts, headache, mood swings, small weight changes and spotting, mostly in the first few cycles. Enzyme-inducing medicines such as rifampicin, carbamazepine, phenytoin and St John's wort speed up the clearance of both hormones and can reduce protection. The oestrogen can also lower the blood level of the epilepsy medicine lamotrigine. Combined pills are not a match for anyone with hormone-sensitive cancer or serious liver disease.