Non-steroidal progesterone receptor specific ligands.

The nuclear receptor for progesterone is a target for contraception and for several therapeutic indications. Progestin agonists and antagonists in clinical use mimic the steroidal backbone of the cognate ligand, progesterone. Thus, they have significant cross-reactivity with other steroid receptors. Recently, non-steroidal progesterone receptor ligands have begun to appear in the literature. This review will describe the current status of research into these promising new chemical entities.