Huh. It must be the artificial progestin, because the estrogen used is a pretty common estrogen, and the stuff in the pill is chemically the same as what you make (although since you eat it, it is passed through the liver, which in this case converts it to a less common estrogen.)
My money’s on the progestin.
Drospirenone is a derivative of spironolactone, which is known as a potassium-sparing diuretic. It (spironolactoe) also has a mild testosterone-blocking effect, which means that it can also be used for some people for acne treatment or polycystic ovary syndrome, which does terrible things to women’s hormone balances. The original plan was to use this as the BCP of choice for women who had these issues.
That’s wonderful news!