The Women’s Health Initiative (WHI) study enrolled more then 160,000 women starting in 1993. This study was paid for and sponsored by the pharmaceutical company that makes PremPro. Synthetic estrogens such as premarin are derived from the urine of pregnant mares, leading to the word breakdown: Pregnant Mare’s Urine. These estrogens contain many estrogens found in horses and not in humans. A lot of women are unable to tolerate the side effects of taking these horse estrogens. The study was stopped in 2002 when it became evident that there was an unmistakable increase in heart disease, breast cancer, stroke and blood clots in women taking this medication. The unfortunate conclusion was drawn that hormone replacement therapy for women is bad, and that it should be stopped. Just like that, women stopped taking estrogen.

The Truth Behind The WHI Study


  • Only the women on synthetic estrogen and progesterone (also known as progestin) suffered adverse results to their health. These synthetic progestins are also known as Premarin and Provera. Those on estrogen only did not suffer adverse effects such as cancer or heart disease.
  • Since women in the estrogen-only study had no increased risks this showed that it was the synthetic progestin (provera) that was the culprit NOT estrogen.
  • Those in the study who started hormone treatment at younger ages experienced positive results, including a decrease in breast cancer.
  • The majority of the women in the study were overweight. Fat cells contain estrogen and the more fat cells a woman has will increase their risk of cancers due this extra estrogen.
  • The results were skewed by the high percentage of women who dropped out of the study (42%).
  • The women in the study took the medication orally, which researchers later found was in part responsible for adverse results.

And the list goes on.

The Great News About Estrogen

Numerous studies have emerged since the WHI study that attest to the safety and health benefits of estrogen replacement. We have numerous articles that attest to the health benefits of hormone replacement of estrogen.

What We’ve Learned About Estrogen

Never liken synthetic estrogen with natural estrogen. Physicians and media tend tie these two together, but they are not the same. The dangers of estrogen replacement have been significantly overstated and misrepresented. What is most important is that other hormones are balanced with estrogen, especially bioidentical progesterone. Synthetic progesterone is what is dangerous in this whole equation not estrogen. Contact us to learn more about estrogen and estrogen replacement.