Are "Natural" Hormones Safer?


Section: healthy woman "My doctor recommended I use bio-identical hormones for relief of menopausal symptoms, claiming they're safer. What are they?"

Bio-identical means the estrogen and progesterone in the product are identical in chemical structure to what your body produces. To make them, hormonelike compounds are extracted from plant sources such as soy and converted in a lab to a carbon copy of your body's hormones. They're often referred to as "natural," a confusing term that only means something is of animal, mineral, or plant origin, not that a substance is natural to your body.

Proponents of these hormones claim they have fewer risks and side effects than the hormones used, for example, in the Women's Health Initiative. That's the landmark study of one type of combination estrogen/progesterone hormone therapy that concluded last year that the risks associated with this particular hormone therapy outweighed the benefits. (Those risks included a small increase in heart attacks, strokes, and breast cancer, while the benefits included a reduction in colon cancer risk and bone fractures due to osteoporosis.)

The WHI study used Prempro, a combination of estrogen derived from pregnant horses' urine and a synthetic progesterone called medroxyprogesterone acetate. But without head-to-head comparison studies between Prempro and bio-identical hormones, we don't know if the latter are any safer.

Given the choice, I'd still prefer to prescribe a product that contains estradiol, the same form of estrogen my ovaries make. It's as close to being bio-identical as you can get. Estradiol is available by prescription in pill or patch form. Some examples include Estrace, Vivelle, Estraderm, Climara, Alora, and Esclim. Bio-identical progesterone is also available as Prometrium (pill) and Crinone (vaginal gel).

In terms of how to take estradiol, the patch delivers estradiol directly to your bloodstream, just as your ovaries do. As a result, it eliminates two of the side effects of oral estrogen: increased triglycerides, a type of blood fat that can trigger a heart attack or stroke, and increased levels of Creactive protein, a marker of inflammation and predictor of heart disease and stroke.

PHOTO (COLOR): Estradiol patches: as close to Mother Nature as possible


By Mary Jane Minkin, MD

Mary Jane Minkin, MD, is a board-certified obstetrician-gynecologist in New Haven, CT, clinical professor at Yale University School of Medicine, and coauthor of The Yale Guide to Women's Reproductive Health (Yale University Press, 2003).

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