Long-acting contraceptive agents: norethisterone esters of polyunsaturated acids

Some new derivatives of norethisterone (17 alpha-ethynyl-17 beta-hydroxyestr-4-en-3-one) are described in which the 17 beta-hydroxyl group of the steroid is esterified with polyunsaturated aliphatic acids. The potential of these compounds as long-acting contraceptive agents has been evaluated.