BioIdentical Hormones – Be Informed!

Bioidentical hormones isn’t a scientific term and it means different things to different people. The Endocrine Society defines bioidentical hormones (BH) as “compounds that have exactly the same chemical and molecular structure as hormones that are produced in the human body.” The FDA (Food and Drug Administration) doesn’t recognize the term bioidentical and regards it as a marketing term. NAMS (North American Menopause Society) states that bioidentical “refers to all hormones that are chemically identical to those made in the human body” and “some well-tested, government-approved, brand-name prescription hormones meet the definition of bioidentical”. There’s no official, standardized definition for bioidentical hormones and this causes a lot of confusion and misinformation. Some women believe:

1. Bioidenticals hormones are compounded in a pharmacy and therefore are different from hormones manufactured by pharmaceutical companies.
2. BHT is natural, therefore is safe
3. BHT is made from plants or herbs, like yams, soy or chasteberry and doesn’t contain hormones


I have not been paid, endorsed, or subsidized by any pharmaceutical company or compounding pharmacy to write this blog. My intention is not to endorse a particular product over another, my goal is to educate, bring awareness, inform, and demystify some common beliefs about bioidentical therapy (BHT). I will write several blogs on the topic and in the first I’ll try to answer the following question:

1. Are the bioidentical hormones (BH) used by local pharmacies to compound formulations different from the BH used by pharmaceutical companies in commercially-available products?

Estrogens, (estradiol, estriol and estrone), progesterone, and testosterone are some of the hormones produced by the human body. Medications that provide any of these ingredients can be considered bioidentical. Several pharmaceutical companies manufacture commercially-available medications that contain some of these hormones. There are no hormones in the wild that can be used by women straight from the plant source. The source of the bioidentical may be a plant like yams or soybeans, but in order for it to have an effect in the human body it has to be synthetized and converted into a chemical with a structure similar to a human hormone. This is done in a few laboratories in the world- they synthesise plant extracts into hormones and sell them to pharmaceutical companies and compounding pharmacies which in turn compound them into products that are sold in different forms e.g., capsules, tablets, creams, and others. Pharmacies and big pharmaceutical companies use the same hormone ingredients to make their products. In other words, bioidentical hormone therapy (BHT) products custom-compounded in the pharmacy contain the same hormones found in commercially-available products. Why should women buy custom-made compounded BHT, usually more expensive, and not covered by private insurance? Compounding pharmacies can formulate products for women with allergies to a commercially-available product, individualize dosing and combinations of hormones, create products without binders, dyes, or preservatives, and compound medications with different routes of administration. However, women must be cautious with custom-made, unregulated BHT. I will discuss issues of safety in another blog; in this blog I want to bring awareness about how the same hormone can have very different effects depending on the route of administration. The route of administration is the way the drug is delivered to the body, e.g., by mouth, by injection, intravenously, or topically (cream, ointments or gels).

Mortar and pestle

For compounding bioidentical hormone products

Women with an intact uterus who are taking systemic (tablets, patches, or gels) estrogen therapy for menopause symptoms must also take a progestogen (natural progesterone or a synthetic progestin) to prevent overgrowth of the lining of the uterus (endometrium). Overgrowth of the endometrium- endometrial hyperplasia- may lead to uterine cancer. The estrogen acts like a fertilizer and thickens the endometrium and the progesterone is the lawn mower, it must be taken to prevent endometrial overgrowth. The most commonly prescribed progestogen is progesterone, the brand name is Prometrium—capsules of micronized progesterone.  It is government-approved and sold by prescription only. In order for Prometrium to be approved by FDA and Health Canada, the pharmaceutical company that developed this product had to present data from randomized control trials showing that this formulation—capsules of micronized progesterone—was used in the trials, and data obtained supports the evidence that micronized progesterone taken by mouth prevents endometrial growth. We should not extrapolate the results of the trials done with capsules of micronized progesterone to progesterone used topically—applied to the skin. Data on progesterone applied to the skin is scarce and there’s no good evidence that progesterone used this way is effective at preventing endometrial overgrowth, and potentially cancer, in women also taking systemic estrogen. Hence, if a woman with an intact uterus takes estrogen therapy and uses progesterone cream she may not be protecting her endometrium from overgrowth—the amount of progesterone absorbed through the skin may not be sufficient to “mow the lawn” and the endometrium may grow unchecked with a resulting increase in the risk of uterine cancer. This is one example of how the same hormone, progesterone, manufactured into capsules by pharmaceutical companies and into unapproved creams, can act differently, and have very different health outcomes, depending on the route of administration. Bioidentical hormone therapy (BHT) employs the same hormones e.g., estradiol, estriol, estrone, and progesterone, whether it is compounded in a community pharmacy or a big pharmaceutical company. Women have choices:  they can buy commercialized or custom-made products but they should educate themselves—learn from reputable, science- and evidence-based, reliable resources—before choosing a product. Women should question BH compounders about the ingredients used in the products and demand proof of efficacy and safety of BHT. Being informed about bioidentical therapy may be the difference between developing uterine cancer and not… Be informed, be safe! Want to know more about bioidenticals or hormone therapy in general? Contact me.


The second blog of this series Bioidentical-Be informed! is

2. BioIdentical Hormones – Be Informed! Part 2: Biodentical Hormone Therapy is natural, therefore bioidentical therapy is safe. Is it?

and the third blog in the series is

3. BioIdentical Hormones – Be Informed! Part 3:  HT is made from plants or herbs, like yams, soy, or chasteberry. Bioidentical hormone therapy doesn’t contain drugs. Does it?




Teresa Isabel Dias BSc Pharm, RPh, NCMP Pharmacist and Certified Menopause Practitioner

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MenopausED was founded by Teresa Isabel Dias, pharmacist and certified menopause practitioner, to help women experiencing menopause challenges.

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