BAY-899 is an orally active and selective antagonist of the luteinizing hormone receptor (LH-R), with IC50 values of 185 nM for human LH (hLH) and 46 nM for rat LH (rLH). In vivo studies have shown that BAY-899 effectively reduces sex hormone levels[1].

LH (human):185 nM , LH (rat):46nM

BAY-899, administered orally at a dosage of 12.5 mg/kg/day for 8 days, effectively reduces serum estradiol levels in intact female rats. In both female and male Wistar rats, BAY-899 demonstrates a half-life (t 1/2) of 11 hours when given intravenously (iv) at 0.5 mg/kg and 12 hours when administered orally (po) at 2 mg/kg. Additionally, the maximum concentration (Cmax) achieved is 0.97 kg/L for the intravenous route and 0.24 kg/L for the oral route.