Synthetic, Natural, and Bioidentical Hormones
Voltaire said, “If you wish to converse with me define your terms”. Â Nothing could be more true when it comes to discussing hormones. Now that we have about 110 posts on this website related to hormones I figured it was finally time to define the differences between, “synthetic”, “natural”, and “bioidentical” hormones. Better late than never.
Here’s why it’s important to define these terms. Bioidentical hormones can be natural or synthetic. And, natural hormones may not be bioidentical hormones. I actually like to use a fourth term – “non-bioidentical” to prevent confusion. How’s that for making this less confusing?
What you want to know at the end of the day is this. Is this hormone replacement I’m taking identical to what my body makes (bioidentical), or not the same as my body makes (non-bioidentical)? That’s why I prefer to use the terms “bioidentical” and “non-bioidentical”. It gets to the crux of the matter.
Premarin: Natural but not Bioidentical
Some physicians refer to bioidentical hormones as “natural hormones”. And, they refer to non-bioidentical hormones as “synthetic hormones”. That’s ok if they let you know what they mean, but strictly speaking, it’s not correct. Here are a few examples why it’s not correct.
Premarin contains several estrogens. Estrogen is a family of hormones. The human female makes 3 main types of estrogens – estrone, estradiol, and estriol. Also, known as E1, E2, and E3 respectively. Premarin comes from the urine of pregnant mares, thus the name Premarin. So Premarin is natural in the sense that it is formed in nature and is not formulated in a lab (synthetic), but it is not completely bioidentical to the human female. In does contain estrone and some estradiol, but also contains several other estrogens that only horses make (at least one of which is carcinogenic in humans) and that the human female does not make.
Search “what’s in premarin?” and see what you find. And, then decide if you want to take it, that’s if you’re a female. And, then share that information with a woman you know who takes Premarin.
Bioidentical Hormones are Synthetically Made
Most bioidentical hormones (estrogens, progesterone, testosterone, DHEA) are synthetically made in a lab and derived from a plant steroid call diosgenin found in yams. Through a series of reactions diosgenin is transformed into the many different sex hormones exactly identical to what we make in the human body – thus “bioidentical”. So they are bioidentical hormones yet synthetically made.
But, not all synthetically made hormones are bioidentical. Progestins, which are not the same as progesterone are synthetically made, and not bio-identical. Examples include the progestins medroxyprogesterone (Provera) even though it uses “progesterone” in the name and levonorgestrel, and the estrogen diethylstilbestrol.
Non-Bioidentical and Bioidentical Hormones
Whether a hormone is naturally or synthetically made is really immaterial. What matters is this. Is it identical to what the human body makes or not?  That’s why I like to use the terms “non-bioidentical” and “bioidentical” hormones.
The $64,000 Question
Why do pharmceutical companies make non-bioidentical hormones when it’s just as easy, if not easier, to make bioidentical hormones? Why mass produce something the human female body does not make?
Answer: primarily for profits. Pharmaceuticals cannot receive a patent for producing a drug identical to something the body naturally makes. So they tweak a hormone so it is not something the body makes, for instance. Â By doing so they can get a patent and charge higher prices during the life the patent is valid. But, by modifying a naturally occurring molecule they potentially change the effects of the drug while raising its side effect profile.
