Our body makes it all the time and it plays a major role .It is not exclusively a female hormone nor is it only a sex hormone. It is infact the precursor to the sex hormone , estrogen and testosterone.It regulates blood sugar, develops intelligence, builds bone and brain activities. It is secreted primarily by the ovaries in females and testes in males.There are no great quantitative differences between men and women ( atleast outside the luteal phase).It was not until 1943 that progesterone was made from plant steroid diosgenin .Once it was established that it could be made like this, biochemists began converting it into other hormones like cortisone, testosterone, estrogen and ofcourse the unnatural progestins and progestogens that masquerades as natural progesterone. There is a misconception that the difference between the natural one (made out of plant ) and the altered is just in their spelling. There is much confusion in the minds of many and even the medical field about this.This is not meant as a condemnation. They are just a busy bunch and it is a specialized subject. It is just as a caution to not take everything you hear about these hormones at their face value. Progesterone has a unique molecular structure whereas progestin and progestogens have their structure altered but the latter may look similar to the real thing.Just as ivy and spinach are both green and leafy.(Ivy quiche anyone?) need any other proof? The fact is progestin behave in radically different ways in our body than progesterone. The only similarity is their ability to maintain the endometrial lining.This also means that they can be patented and sold for exhorbitant prices. progestins are potentially toxic because of their altered molecular structure. Some of the side effects are increased risk of abortion and congenital abnormalities if taken by pregnant women, fluid retention, migraine, asthma, epilepsy, cardiac and renal dysfunction, depression, breast tenderness, nausea, insomnia, cancer, and a drop in progesterone levels.There are long term side effects on adrenal glands, liver , ovaries and in uterine function The key messsage is natural progesterone is just like what your body makes and is a unique substance with unique properties that cannot be faked !