When it comes to treating female reproductive and menstrual problems, hormone therapies play a crucial role in managing various menstrual and reproductive issues. However, the choice between progestins and bioidentical progesterone can significantly impact health outcomes. Understanding the differences between these two types of hormone treatments is essential for making informed decisions about your health. In this blog post, we’ll explore the distinctions between synthetic progestins like Provera and bioidentical progesterone such as Prometrium, their effects, uses, and why bioidentical progesterone is preferred and used by natural family planning (NFP) physicians for treatment of female reproductive issues.
What Are Progestins and Bioidentical Progesterone?
Progestins are synthetic hormones designed to mimic the effects of natural progesterone but differ in their chemical structure. Progestins work by mimicking progesterone, but their altered structure can result in different interactions with progesterone receptors in the body. Furthermore, the synthetic nature of progestins means they can also interact with other hormone receptors, sometimes leading to unwanted effects such as mood swings, weight gain, lipid changes (decreased HDL or "good cholesterol") and insulin resistance. Commonly used in hormonal contraceptives and hormone replacement therapy, progestins include medications like Provera (medroxyprogesterone acetate).
Bioidentical Progesterone, such as Prometrium, is chemically identical to the progesterone produced naturally by the ovaries. It is derived from natural sources such as plants and is designed to match the molecular structure of endogenous progesterone exactly. Because bioidentical progesterone is structurally identical to natural progesterone, it interacts with progesterone receptors in a way that closely mimics the body’s natural hormonal activity, making it a preferred choice in bioidentical hormone replacement therapy (BHRT). Bioidentical progesterone is also used to treat menopausal symptoms, support pregnancy in cases of progesterone deficiency, and to manage conditions like premenstrual syndrome (PMS) and perimenopausal symptoms. Unlike progestins, bioidentical progesterone is not used within hormonal birth control.
Negative Effects of Progestins
Progestins have been associated with various side effects and risks, particularly when used long-term. Common issues include:
Cardiovascular Risks: Studies have shown that certain progestins can increase the risk of blood clots, stroke, and heart attacks. A notable example is the increased risk of cardiovascular problems in women using certain types of hormonal birth control containing progestins. A study in the Journal of the American Medical Association (JAMA) found that certain progestins used in HRT were linked to higher cardiovascular risks compared to bioidentical progesterone (Rossouw et al., 2002).
Breast Cancer: Synthetic progestins have been linked to an increased risk of breast cancer. The Women's Health Initiative (WHI) study showed a higher incidence of breast cancer in women using combined estrogen-progestin therapy compared to those using estrogen alone or bioidentical progesterone (Chlebowski et al., 2003).
Mood Disturbances: Progestins can cause mood swings, depression, and anxiety in some women. This can be attributed to the way synthetic hormones affect neurotransmitter function and stress response.
Lowers Natural Progesterone Levels: Progesterone is a hormone that is produced by the corpus luteum within the ovaries after ovulation has occurred. If a woman is taking progestins in the form of hormonal contraceptives, this prevents her from ovulating and therefore producing natural progesterone. These women will only be getting progestins in this case, which can therefore lead to lower natural progesterone levels.
Click here to read my blog post with even more information about the increased risks of birth control and its side effects as published by the pharmaceutical companies themselves.
Why Bioidentical Progesterone is Preferred
Bioidentical progesterone is generally considered safer and more effective for treating hormonal imbalances related to menstruation and menopause. Its benefits include:
Natural Hormonal Balance: Because bioidentical progesterone is identical to the body’s own hormone, it is better utilized and less likely to cause hormonal imbalance or unexpected side effects.  An article in the Journal of Women's Health highlighted the advantages of bioidentical hormone therapy, emphasizing its safety and efficacy (Holtorf, 2009).
Lower Risk Profile: Studies suggest that bioidentical progesterone has a lower risk of adverse effects, including cardiovascular issues and breast cancer. A study published in Climacteric showed that bioidentical progesterone did not increase the risk of breast cancer and had a safer profile compared to synthetic progestins (Fournier et al., 2005). In fact, according to clinical studies performed by the Women's Health Initiative (WHI) and published by the FDA, the use of combined oral contraceptives (birth control pills containing progestins) caused a 31% increased risk of stroke, 95% increased risk of deep vein thrombosis (blood clots in arms or legs), 113% increased risk of pulmonary embolisms (blood clot in lungs), and a 24% increased risk of invasive breast cancer compared to placebo. Additionally, as published in Medscape, other clinical studies have shown that while estrogen plus progestins causes a relative risk of 1.28 (28% increased risk) of breast cancer, estrogen plus bioidentical progesterone caused no increased risk of breast cancer.
Protective Effects: Research indicates that bioidentical progesterone has protective effects against breast cancer and cardiovascular diseases, unlike some synthetic progestins. Additionally, bioidentical progesterone has been linked to lower rates of colon cancer and uterine cancer as well (Lieberman, 2017).
Better for Mental Health: Bioidentical progesterone does not have the same negative impacts on mood that are often associated with progestins. Bioidentical progesterone has been shown to have a more favorable impact on mood and cognitive function.
Conclusion
When it comes to managing menstrual and reproductive health, it is crucial to understand the difference between progestins and bioidentical progesterone. Bioidentical progesterone offers a safer and more natural option, aligning more closely with the body’s own hormone production. Progestins, which are synthetic progesterone, are associated with negative side effects and increased risk of breast cancer and cardiovascular events. Make sure to establish care with an NFP (Natural Family Planning) Physician or Napro Medical consultant as these physicians are educated in and use bioidentical hormones rather than progestins. By staying informed and consulting with knowledgeable healthcare providers, women can make choices that support their health and well-being.
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