What are Bioidentical Hormones

As we age, hormone production from our ovaries and adrenal glands begins to decline. This leads to alterations in estradiol progesterone testosterone, DHEA, DHEAS, cortisol, pregnenolone and thyroid hormones. Bioidentical hormones may be utilized to support age related changes in these hormones.

There is a lack of consensus as to what the term “bioidentical” actually means. It has been proposed that bioidentical hormones are substances that are identical in molecular structure to human hormones. Bioidentical hormones are not found in this form in nature but are made, or synthesized, from a plant chemical extracted from yams and soy. The FDA refers to bioidentical therapy as a “marketing” term and not a medical one. We would also propose that the term refers to a broader, more diverse, specific and customized from of hormone therapy.

Traditional hormone therapy has only focused on supplementing estrogen in women.

  • 1929 Estrogen is isolated

  • 1930 Water soluble estrogens are derived from pregnant mares’ urine

  • 1933 The first estrogen replacement therapy is marketed

  • 1934 Progesterone is first used

  • 1943 Premarin, derived from pregnant mares’ urine, is marketed by Wyeth

  • 1975 Micronized estradiol for oral use is marketed

  • 1992 Premarin is the most widely marketed drug in the United States

  • 1997 Dr. Jonathan Wright introduces the concept of bio-identical hormone replacement therapy (BHRT) with the book Natural Hormone Replacement for Women Over 45 (Wright JVW, Morgenthaler J. Smart Publications, 1997)

  • 2002 The U.S Government sponsored Women’s Health Initiative study is published which concludes that the risks of hormone replacement therapy with Premarin and Provera (a synthetic progestin) in the form of Prempro outweigh the benefits. Unfortunately, the study has many flaws however hormone therapy prescriptions plummet.

  • 2006 Bioidentical hormone therapies gain popularity as there is increasing dissatisfaction with synthetic preparations.

Bioidentical hormones are designed to be structurally the same as the ones that our body produces in an effort to better match the functions that theses hormones serve in our body.

  • There are three types of estrogen produced in the female body; Estradiol (E2) Estriol (E3) Estrone (E1). Estradiol (E2) is the major estrogen produced by the ovary. Estradiol may help to prevent cardiac disease, cognitive decline, improve mood and lessen anxiety. Estradiol affects many organ systems and its impact continues to be elucidated. Estriol is produced during pregnancy. Estrone is produced mainly in the subcutaneous tissues and is the predominant estrogen circulating after menopause.

  • Progesterone (P4) is produced predominantly by the ovaries, but also in the adrenal glands and levels decline with aging. Progesterone may have a calming effect, improve sleep, act as a diuretic, affect metabolism and affect thyroid function.  

  • Testosterone production in women occurs mainly in the adrenal glands, but also the ovaries. It can be important in mood, giving one a sense of well-being, improve libido, build muscle mass, strengthen bones, act in brain function,

  • DHEA-S is produced by the adrenal glands. DHEA is produced in the adrenal glands, the ovaries and the brain. DHEA may act in inflammation and immune modulating pathways, It is important in sexual functioning, sleep, and cholesterol metabolism,

  • Pregnenolone (P5) is synthesized from cholesterol and is a precursor to progesterone, androgens, estrogens, glucocorticoids and mineralcorticoids. It is also a neurosteroid and has direct action on the brain. It is made largely in the adrenal cortex, but also in the ovaries and brain.

In contrast to standard hormone preparations which usually combine estradiol with progesterone, bioidentical hormone (BHRT) preparations usually contain mixtures of the above hormones, prescribed in a highly individualized fashion.

In contrast to standard preparations which are available at a standard pharmacy, BHRT is composed on an individualized basis by a compounding pharmacist and may contain multiple combinations of the above listed hormones.

Some BHRT preparations such as oral progesterone, vaginal progesterone and estradiol are available in standard FDA approved preparations.

Transdermal progesterone may have significant benefits for some women is not available in a standard FDA form. Testosterone, DHEA, and pregnenolone are not available for women in an FDA approved preparation.

BHRT may be prescribed in transdermal, transmucosal or oral forms.

BHRT is currently not an FDA approved type of medication. This may change in the near future with new delivery systems.

While claims have been made that BHRT is safer, there have been no studies to demonstrate this. Risks continue to be possible induction of estrogen dependent malignancies such as breast and uterine cancers. Clotting risks such as deep venous thrombosis and stroke. The risks and benefits of any hormone preparations are modified by the dosing, mode of delivery, and metabolism.

Advantage of BHRT is that it can be intricately adjusted to help to support the body. For this reason, they may be more efficacious.

Synthetic progestins prescribed in standard therapies may have detrimental effects for women such as mood cognitive function and lipid profiles.

Generally with BHRT, laboratory values of hormone levels are used to help guide treatment, not to dose to specifically. The optimal levels are not well defined. Serum, urine or salivary testing can be conducted in order to help manage dosing, but not to specifically define dosing.

The benefit and safety of any hormonal preparation depends on how the hormone is made and prescribed. It is important to find an individual who is experienced in BHRT management and can analyze and dose appropriately, This individual should also work with a safe, reliable and ethical compounding pharmacist.