From the Guidelines
Bioidentical Estrogen Replacement Therapy
Bioidentical estrogen replacement therapy involves the use of hormones that are structurally identical to those produced by the human body, such as estradiol and estriol [ 1 ].
- Commonly prescribed bio-identical estrogen medications include Estrace (estradiol) 0.5-2mg orally daily, and Bi-Est (estriol/estradiol) 0.5-2mg orally daily, with typical treatment durations ranging from 6-12 months [ 1 ].
- Dosing may be adjusted based on individual patient response and symptom severity, with some patients requiring continuous therapy and others benefiting from cyclic regimens.
- The transdermal administration of 17βE seems to be the preferred route as it mimics the physiological serum estradiol concentrations providing a better safety profile than oral formulations [ 1 ].
- It is worth noting that the FDA has not approved any type or class of bioidentical hormone therapy for the prevention of chronic diseases in postmenopausal women, and the safety and effectiveness of these products have not been evaluated through the FDA's drug approval process [ 1 ].
From the FDA Drug Label
There is no evidence that the use of “natural” estrogens results in a different endometrial risk profile than “synthetic” estrogens at equivalent estrogen doses.
Bioidentical estrogen replacement therapy refers to the use of estrogens that are identical in structure to the natural estrogens produced by the body. However, the provided drug labels do not provide information on the specific characteristics or benefits of bioidentical estrogen replacement therapy. The FDA drug label does not answer the question.
From the Research
Definition of Bioidentical Estrogen Replacement Therapy
- Bioidentical hormone therapy (BHT) uses bioidentical hormones (BHs), derivatives of plant extracts chemically modified to be structurally indistinguishable from human endogenous hormones 2.
- Bioidentical hormones include estriol, estrone, estradiol, testosterone, micronized progesterone, and occasionally dehydroepiandrosterone (DHEA) 2.
- Bioidentical estrogen replacement therapy refers to the use of these bioidentical hormones, specifically estriol, estrone, and estradiol, to replace estrogen in the body.
Characteristics of Bioidentical Estrogen Replacement Therapy
- Bioidentical hormones are available commercially or can be compounded into different dosages and for different routes of administration 2.
- Compounded preparations of bioidentical hormones may be customized based on saliva tests or blood sera levels, although this approach is not supported by evidence-based guidelines 2, 3.
- Proponents of bioidentical hormone therapy claim that it is natural and safer than synthetic hormones, but there is little evidence to support this belief 4, 3.
Comparison with Conventional Hormone Therapies
- Estrogen-based hormone therapies, including bioidentical and conventional hormone therapies, share similar efficacies as well as risks 2.
- Some studies suggest that bioidentical hormones may be associated with lower risks, including the risk of breast cancer and cardiovascular disease, and are more efficacious than their synthetic and animal-derived counterparts 5.
- However, other studies have found that there is no scientific evidence to support claims of greater efficacy and safety of bioidentical hormone therapy compared to conventional hormone therapies 2, 6.