[The characteristics of triphasic estrogen-progesterone contraceptives and their theoretical indications].

In the long history of oral contraception, unfortunate events have been associated with the use of oestrogens and progestogens. The discovery of new progestational hormones with weak androgenic activity but powerful progestational action has led to the combination of very low doses of ethinyloestradiol with low doses of progestational hormones which progressively increase in three successive stages. The products thus show excellent safety, accompanied by a minimum of incidents, and are extremely reliable contraceptives.