What is Bioidentical Hormones?

Bioidentical hormones have a structure that is exactly the same as the structure of the hormone naturally secreted by the body. In contrast, the structure of non-bioidentical hormones differs from  bioidentical hormone.

Most are synthetically modified for example, ethinylestradiol that is used in birth control pills. It is a synthetic derivative of the natural female hormone, estradiol. Non-bioidentical hormones may also be natural hormones and differ from human estradiol. They can come from another species such as conjugated estrogens that come from the urine of pregnant mares.  

Non-bioidentical hormones have different structures from bioidentical hormones. The different structure can cause excessive binding or unstable and incomplete binding to the hormone receptor sites and therefore cause different effects.

In addition, as the human liver was not meant to process these hormones, the breakdown of non-bioidentical derivatives often takes place at a slower pace, permitting these hormones to accumulate in the body.

In certain circumstances, this slow breakdown provides an advantage compared to bioidentical hormones that may be broken down too quickly. Nevertheless, the slow and difficult breakdown may lead to adverse effects as well such as liver damage by hormones accumulating in the liver or the promotion of breast cancer by synthetic progestogens.