How is bioidentical HRT different from conventional HRT?
Bioidentical HRT uses estrogens that are exact chemical replicas of estrogens produced by the human body. Conventional HRT uses conjugated estrogens, so-called because they come from horse urine and are not chemically identical to human estrogens. Premarin, the drug whose safety was brought into question in last month’s study, got its name from the phrase “pregnant mare urine.” Q: Does it completely replace all the hormones lost after menopause? A: No. The human body makes dozens of types of estrogen; natural HRT replaces only three of them: estrone, estradiol and estriol. About 80 percent of estrogen circulating in the blood stream is estriol. The majority of the remaining 20 percent is estrone and estradiol, with other types of estrogens circulating in smaller amounts. Premarin also has dozens of different types of estrogens, though these are horse estrogens and are not chemically identical to human estrogens. Q: Where do the three estrogens in bioidentical HRT come from? A: The gian
