All,
I am the endocrine expert at a Fortune 50 Industrial Company that has 55,000 products and sales of $31 billion. I have PhDs in Analytical Chemistry, Inorganic Chemistry and Molecular Toxicology. Part of my job is to make sure nothing we produce interacts with the endocrine system. That means I know a lot about how it works and how it works in conjunction with metabolism.
Last I looked (about 8 months ago) there were 18 estrogen types available for use. All had purported advantages and disadvantages. You and your doctor have to find a delivery mechanism and a type of estrogen that works for you. You also have to determine the levels you should be at as there is no real agreement out there in the medical community. This is in part because the effectiveness of E is also dependant on the levels of T and possibly progesterone (plus others that no one talks about but that I have to worry about) so things get complicated. A rule of thumb in the medical community seems to be female normal if progesterone is included. Female normal +20% E and -50% T if no progesterone. Injections are tried and true. Pills can be good but may not be. Blah, blah, find the one that works.
As far as "bioidentical hormones" From Harvard Medical Publications – 2006 – "The interest in a more natural approach to hormone therapy has focused attention on bioidentical hormones — hormones that are identical in molecular structure to the hormones women make in their bodies. They're not found in this form in nature but are made, or synthesized, from a plant chemical extracted from yams and soy. Bioidentical estrogens are 17 beta-estradiol, estrone, and estriol. (Estradiol is the form of estrogen that decreases at menopause.) Bioidentical progesterone is simply progesterone. It's micronized (finely ground) in the laboratory for better absorption in the body.
Bioidentical hormone therapy is often called "natural hormone therapy" because bioidentical hormones act in the body just like the hormones we produce. But here again, that tricky word natural muddies the waters. Pregnant mares' urine is natural, but Premarin is not bioidentical, at least not to human estrogen. The same goes for Cenestin, which is made from plants but is not bioidentical.
Technically, the body can't distinguish bioidentical hormones from the ones your ovaries produce. On a blood test, your total estradiol reflects the bioidentical estradiol you've taken as well as the estradiol your body makes. On the other hand, Premarin is metabolized into various forms of estrogen that aren't measured by standard laboratory tests. Proponents of bioidentical hormones say that one advantage of bioidentical estrogen over Premarin is that estrogen levels can be monitored more precisely and treatment individualized accordingly. Skeptics counter that it hardly matters, because no one knows exactly what hormone levels to aim for, and symptoms, not levels, should be treated and monitored." To me, there is identical and non-identical. Then there is what I am concerned about..how reactive is that substance when compared to estradiol, esterone and estriol?..what is the bioavailability compared to estradiol, esterone and estriol? Plus another 20 or so other questions. A person can crank around doses of things to get more or less the same effect. Which is what doctors are doing - for good or bad.
Me? I use a "bioidentical" estrogen cream. I do have a metabolic disorder. It's one of the problems DES sons sometimes have. I'm also allergic to the acrylates that are used in patches. The sublingual method should work but I'd like to see data from controlled trials not guesses made by a doctor. I'd do injections if I needed to but the cream is working fantastic – for me.
Jen