Hormone replacement therapy is in the spotlight. More and more women are seeking information about the possibilities of hormone therapy during the peri- and post-menopause. You quickly come across terms such as bio-identical, body-identical, body-own, natural and synthetic.
Interestingly, these terms are not only used interchangeably on the internet and social media, but also by healthcare providers, trainers and experts. This makes it difficult for patients to understand what it is actually about. Are bio-identical hormones the same as body-identical hormones? Are they natural? Are they made specifically for each patient? And are they synthetic or not?
The answer is more nuanced than is often thought.
The confusion arises mainly because the same words have different meanings in different contexts. For example, bio-identical refers to the molecular structure of a hormone, while body-own relates to the origin of the hormone. The word synthetic is also used in two different ways: chemists mean that a substance is made in a laboratory, while doctors usually mean a synthetic hormone that has a chemical structure that differs from the hormone that the body itself produces.
In this blog, we outline the most important concepts. This clarifies what the terms mean, how they differ from each other, and why it is important not to confuse these concepts. Because a good conversation about hormone therapy begins with clear language.
The most important concepts outlined
1. Endogenous hormones
Endogenous hormones are the hormones produced by your own body. In women, this mainly occurs in the ovaries, in men in the testes, and in both sexes also in the adrenal glands. Examples include oestradiol, progesterone, and testosterone.
When hormone production decreases, for example during menopause, hormone supplementation may be considered. The hormones you use then are not endogenous; they are administered from outside.
2. Body-identical hormones
Body-identical hormones are hormones whose chemical structure is exactly the same as that of the hormones produced by our body.
These hormones are made from plant-based raw materials, such as sterols from wild yam or soy. The plant does not contain the final hormone but provides a raw material that is converted in a laboratory through multiple chemical steps into, for example, oestradiol or progesterone.
Although these hormones are produced in a laboratory, the end product is molecularly indistinguishable from the hormone that the body produces itself.
3. Bio-identical hormones
The term bio-identical means exactly the same as body-identical. Both terms refer to hormones with a molecular structure that is identical to that of the endogenous hormone.
The difference is therefore not in the hormone itself, but mainly in the terminology used. Internationally, the term bio-identical hormones is usually used, while in the Netherlands and Belgium the term body-identical hormones is increasingly being used. The latter term is often clearer for patients.
4. Custom-made bio-identical hormones (compounded BHRT)
This creates a lot of confusion.
Some pharmacies prepare hormones specifically for one patient. The dosage, combination, or method of administration is then tailored to the individual situation. This is often referred to as compounded bio-identical hormone therapy (cBHRT).
Because this treatment has received a lot of attention for many years, many people have come to think that bio-identical automatically means that a hormone is made specifically for them.
That is not correct.
Many registered medicines also contain bio-identical or body-identical hormones. The difference is therefore not in the hormone itself, but in the way the product is prepared and regulated.
5. Natural hormones
The term natural is perhaps the most misleading of all.
Often this means that the raw materials come from plants, such as wild yam or soy. However, the final hormone does not come directly from the plant. First, the plant substances are converted in a laboratory into oestradiol, progesterone, or testosterone.
'Natural' therefore says little about the final medicine and is not a scientific term.
6. Synthetic hormones
The word synthetic is also used in two ways.
From a chemical point of view, almost all hormones used as medication are synthetically produced. They are indeed made in a laboratory.
In medical practice, however, synthetic hormones usually refer to hormones whose molecular structure has been deliberately altered. As a result, they are not identical to the hormones produced by the body itself.
Well-known examples include ethinylestradiol and various progestogens used in contraceptive pills and some forms of hormone therapy.
This distinction is important. A body-identical hormone can therefore be chemically synthetically produced, while its molecular structure is still exactly the same as that of the body's own hormone.
In summary
Term | Meaning |
Body-own hormones | Hormones produced by the body itself. |
Body-identical hormones | Hormones with exactly the same molecular structure as the body's own hormone. |
Bio-identical hormones | International term for body-identical hormones. |
Compounded BHRT | Custom-made preparations with body-identical hormones. |
Natural hormones | Not a scientific term; usually refers to the plant origin of the raw material. |
Synthetic hormones | Hormones made in a laboratory; in medical practice, the term is often used for hormones with an altered molecular structure. |