WHAT ARE BIOIDENTICAL HORMONES?

A survey of female visitors to one of the pharmacies in the United States showed that about half believe that the term “natural” means plant-based. In addition, most believe that bioidentical hormone therapy has fewer side effects or has no risks and may be more effective than conventional menopausal hormone therapy (MHT).

Unfortunately, many women have the wrong idea about bioidentity, believing that it guarantees naturalness and therefore complete safety compared to synthetic forms of hormones.

What are bioidentical hormones?

The source of all endogenous steroid hormones (including sex hormones) in the human body is cholesterol, which comes from food or is produced by the body’s own cells.

Each hormone in the human body has its own receptor through which it works in the body. In the absence of its own, endogenous hormones, this receptor will gladly cooperate with any other molecules identical in structure. At the same time, the source from which the hormone came, as well as its lineage, are of no importance to the receptor.

Plants do not produce cholesterol, but have related chemicals known as plant sterols. Through laboratory enzymatic processing, exogenous (come from outside) steroid hormone products can be obtained from them, which will be recognized by endogenous (internal) hormone receptors in the human body as native, bioidentical hormones.

What is their origin?

Hormones that are structurally and chemically identical to those hormones produced by the human body are called bioidentical. It is implied that the body’s response to such hormones will correspond to the physiological response to its own endogenous hormones.   It is important to remember that it is the chemical structure of the molecule, not the original source, that determines whether a hormone is bioidentical.   Bioidentical hormones can be synthesized from plant (soybeans, yams) or animal (biological fluids and animal tissues) sources or obtained completely chemically. It is important to understand that bioidentical hormone preparations, which are of plant origin and are called “natural”, are also chemically modified in the laboratory.

Phytohormones are a separate topic. Some plants contain non-steroidal hormone-like compounds (isoflavones, coumestans, lignans), which are structurally similar to human hormones (but not identical to them) and are able to bind to the corresponding receptors in the human body. Such herbal preparations are widely used to alleviate the symptoms of menopause, especially in cases where systemic therapy with real hormones is contraindicated. The activity of phytoestrogens is much lower than that of steroid hormones, but it is enough to have some effect.

All hormones used in modern endocrine gynecology can be both bioidentical and non-bioidentical, that is, substances that do not occur in the human body.

For example, the components of hormonal contraceptives are not bioidentical. Combined drugs (COCs) usually contain a synthetic analogue of the female hormone estrogen (ethinyl estradiol) and progesterone (one of many progestins). These substances are able to connect with receptors in the woman’s body, but their effect will differ from the effect of their own hormones, since the purpose of these substances is to prevent pregnancy, that is, to change the physiological effect of endogenous hormones.

To whom we indicate the therapy with bioidentical hormonal drugs?

When there is a deficiency of hormones in the body, the use of bioidentical drugs is the optimal way to compensate. In the case of female sex steroids, these are estrogens and progesterone. Bioidentical estrogens for menopausal or hormone replacement therapy are usually derived from plant sources and are chemically 17-β-estradiol or estradiol valerate. These can be tablets, plasters, gels, injections or depot forms in the form of implants. They will all have the same mechanism of action in the human body, but may differ in bioavailability and pharmacokinetics (rate of absorption, distribution, metabolism and elimination of the drug).

Bioidentical progesterone is micronized progesterone. Its synthetic analogue, widely used in MHT and not only, dydrogesterone, is also obtained from plant raw materials, but according to its chemical structure it is a stereoisomer of progesterone (retroprogesterone), which gives it high efficiency when taken orally (ordinary progesterone is very capricious in this regard), good tolerability and absence of undesirable side effects.

Globally, it does not matter how the drug is derived – by processing natural raw materials or completely synthesized in a laboratory. The final form, structure of the active substance, degree of purification, physico-chemical, biopharmaceutical properties and the ability to bind “purely” to the appropriate receptors in the human body (selectivity) are of fundamental importance. All these factors ensure the effectiveness and safety of the medicinal product.

How effective and safe are they?

The efficacy and safety profile of each new drug is studied for years. Pharmaceutical companies spend a lot of money on this, so that the doctor, recommending this or that drug to you, can rely on research with a high level of evidence. In addition, there are organizations such as the FDA (Food and Drug Administration) in the US and the EMA (European Medicines Agency) in Europe that control the quality and safety of pharmaceutical and food products on the market. The inclusion of the drug in the register of medicinal products of these organizations is a kind of sign of product quality. This is very important to consider when deciding on the use of hormonal pellets.

To conclude: 

1. There are no completely “natural” hormonal preparations.
2. A phytopreparation and a hormone obtained from plant raw materials are completely different things.
3. Hormones do not grow on trees and cannot be obtained from drying and grinding leaves or animal gonads. Any natural raw material undergoes complex chemical processing before becoming a bioidentical hormone.
4. Bioidentity is determined by the chemical structure of the substance, not its origin.
5. Bioidentical exogenous hormones can be used to correct the symptoms associated with the deficiency of endogenous hormones, but the effectiveness and safety of the drug can be said after many years of large-scale clinical studies.

The selection and appointment of such drugs should be carried out exclusively by an experienced gynecologist-endocrinologist!