Let’s go back in time to 2002 when The Women’s Health Initiative (WHI), a landmark study that looked at the effect of synthetic hormone replacement therapy and outcomes such as heart attacks and breast cancer, was released. Remember, at that time, women had been told for decades that synthetic hormone replacement therapy would provide benefits without increasing the risk for breast cancer. (Keep in mind there were many previous studies that did report an increase risk in breast cancer with the use of synthetic hormones.) The WHI’s first study found synthetic progesterone in the form of medroxyprogesterone acetate (MPA) significantly increased a woman’s risk of developing breast cancer. (2)
When the 2002 WHI study was first reported it made national headlines in nearly every major newspaper. Doctors stopped prescribing synthetic hormone replacement therapy due to the results. However, most doctors failed to understand the difference between using natural, bioidentical hormones like natural progesterone, and synthetic hormones.