This very informative article is on the website of Dr Christiane Northrup, M.D. It deals with issues regarding the various “labels” used in the field of hormone replacement.
There seems to be a lot of confusion around the definition of “natural” versus “bioidentical” versus “synthetic” hormones. One thing to remember when making this distinction is that “bioidentical” refers to the shape of the molecule itself rather than the source of the hormone. By this, I mean that hormones can be marketed as “natural” or “plant-based,” yet not come near to being “bioidentical” to native human female hormones or performing as such in the body. Examples of this are the numerous proprietary HRT options being marketed as “plant-based” and “natural,” as well as purely yam-based creams.