<p>Lynestrenol is an oral preparation of the synthetic progestagen lynestrenol, which shares various activities with the natural hormone progesterone. Lynestrenol has a strong progestational influence on the endometrium. In addition, it suppresses ovulation and menstruation for as long as the preparation is taken daily without interruption. Lynestrenol can be used in conditions requiring a pronounced progestagenic effect. After oral administration lynestrenol is readily absorbed and subsequently converted into the pharmacologically active norethisterone, through which it exerts its major biological effects. Within 2-4 hours after ingestion of lynestrenol peak plasma levels of norethisterone are reached. Lynestrenol and its metabolites are predominantly excreted in the urine, and to a less extent in the faeces.</p>