Drospirenone is a synthetic hormone used in birth control pills. Drospirenone differs from other synthetic progestins in that its pharmacological profile in preclinical studies shows it to be closer to the natural progesterone. As such it has potent antimineralocorticoid properties, counteracts the estrogen-stimulated activity of the renin-angiotensin-aldosterone system, and has also been shown to possess mild antiandrogen activity. The antimineralocorticoid properties exhibited by drospirenone promote sodium excretion and prevent water retention. Drospirenone is taken orally with about 76% bioavailability. It is bound not by sex hormone-binding globulin or corticosteroid binding globulin, but by other serum proteins. Metabolites have not been shown to be biologically active, show up in urine and feces, and are essentially completely excreted within 10 days.