Natural, bioidentical hormones have the exact same chemical structure as the endogenous hormones that our bodies produce.

By contrast, synthetic hormones have slightly different chemical structures than our hormones.

For instance, the hormone progesterone is produced in the adrenal glands of both men and women, as well as in women’s ovaries. It is then released into the bloodstream, where it travels throughout the body, binding to cell receptors.

Once the hormone binds to its receptor, a chemical reaction occurs. In the bones, when progesterone binds, the bone building cells — called osteoblasts — are stimulated to make new bone tissue.

When a woman is prescribed the synthetic hormone Provera — which is often used as birth control — it also binds to the progesterone receptor.

But the side chains of Provera’s chemical structure make it a foreign substance in the body. It doesn’t fit right on the progesterone receptor. Because it is a foreign substance, Provera does not have the same response when it binds to the progesterone receptor — like building bone tissue.

Worse yet, the body doesn’t have a good detoxification capacity for foreign substances like Provera. Therefore, the synthetic hormone stays in the body much longer than a natural hormone like progesterone.

This long-lasting feature of Provera causes many of the adverse effects of the drug, including increased risk of blood clots, breast cancer, and heart attacks.

Furthermore, there is a risk of irreversible osteoporosis with the use of Provera.

Natural progesterone does not cause these terrible side effects. In 20 years of prescribing natural progesterone, the only (rare) side effects I have seen are breast tenderness and moodiness, both of which are easily alleviated by adjusting the dose.

Progesterone is used in the female body to maintain pregnancy. But even beyond that, the benefits of natural progesterone are many. It helps treat endometriosis, osteoporosis, and PMS symptoms, acts as a natural diuretic, and is a natural antidepressant.

Natural progesterone can facilitate thyroid activation by helping convert inactive (T4) to active (T3) thyroid hormone. I t helps improve libido (in both sexes), maintains proper cell oxygenation, normalizes blood sugar levels, and protects against fibrocystic breast disease.

Unlike Provera, progesterone does not increase the risk of heart attacks. In fact, studies show that progesterone may actually decrease cardiovascular risk.