Selective progesterone receptor modulator

A selective progesterone receptor modulator (SPRM) is an agent that acts on the progesterone receptor. A characteristic that distinguishes such substances from receptor full agonists (such as progesterone) and full antagonists (such as aglepristone) is that their action differs in different tissues (agonist in some while antagonist in others). This mixed agonist/antagonist profile of action leads to selective stimulation or inhibition progesterone-like action in different tissues and furthermore raises the possibility of dissociation of desirable therapeutic effects from undesirable side effects in synthetic progesterone receptor drug candidates.