Dihydrotestosterone is inactivated by conversion to androsterone among other inactive forms. Surplus androgens are disposed of by conjugation as sulfate esters or as glucuronide derivatives. These modifications increase the water solubility allowing for release in urine. Elimination of formate results in aromatization of ring A, to give estradiol . Once ovulation has occurred, the ruptured follicle develops into a structure called the corpus luteum , which starts to produce progesterone.
Progesterone prepares the endometrium for implantation of the fertilized egg .
If implantation occurs, the corpus luteum is maintained, and continues production of progesterone. As the placenta develops, it takes over as the progesterone producer. If there was no fertilization or implantation fails for some reason, the corpus luteum breaks down after a few days and progesterone production ceases. Elevated levels of progesterone are maintained throughout pregnancy, and prepare the body for lactation. In addition, progesterone inhibits the release of the pituitary hormones follicle stimulating hormone FSH and luteininzing hormone LH which would otherwise start the next ovulation cycle.