the use as a testing system of transprogestin or of progesterone-binding protein ( obtained from a pregnant guinea pig ) with a high specificity to progesterone and a number of its affiliated metabolites increased the sensitivity of the method considerably , permitting to determine progestins in the blood and urine of nonpregnant women ( at various phases of the sexual cycle ) and in men .
C0033308
progesterone
C0033306
progestins