Provera is not Progesterone. All AIM Products carry a full Moneyback Guarantee. So a progestin is the word that has been arrived at meaning compounds that have progesterone like properties, but are not progesterone and are synthetic, and you can add to that, they don't have the full spectrum of all of progesterone's benefits, and they are loaded with side effects. So progestin is the name of the artificial synthetic drug that is sold by the doctor thinking it is progesterone.
Real progesterone is the one made from the plants.
Doctors know that real progesterone must be used for invetro fertilizations - Provera won't work. Recent studies have also shown that progesterone protects against coronary spasms and post-menopausal heart attacks and Provera does not provide this protection. The change of one atom in a molecule like progesterone totally changes its function. Yet the typical doctor doesn't seem to grasp that progestins are not progesterone and that any change in the molecule is going to be a drastic change in what it does. I talk with doctors groups and when I show them that progesterone is not Provera they have this stunned look on their face, they don't even know what question to ask.