Apart from premarin which is made from a pregnant mares urine, synthetic hormones are also made from soybeans or wild yams.

In other words the manufactures are taking a perfectly good natural hormone and changing the molecular structure to make them unique, not found in nature so they can be patented and profitable.

Patented drugs are important to drug company profits because the company that invents them can sell them exclusively for many years without competition.

Research shows conventional HRT carries an unacceptable risk of breast cancer, heart attacks and strokes and many other unwanted side effects.

Natural hormones cannot be patented and are less expensive.

Progestin’s are synthetic hormones used in birth control pills and conventional HRT, provera is the most commonly used Progestin  in HRT, PremPro the most conventional HRT  using a  combination of Premarin and Provera.