But, Liu added, "the main problem is how a woman would obtain [bio-identicals]. If it's pharmaceutical grade, FDA-grade, it's prescribed. It's just how it's made."
Some of the bio-identical hormones are "compounded," meaning they are mixed specially to meet an individual's needs. For example, some dyes or preservatives may be eliminated if a person is allergic to them, according to the FDA.
"The pharmacist assumes that responsibility and the physician should specify that on the prescription," Liu said. So the bio-identical product may not have exactly the same ingredients as a standard product, he said.
But be leery if a pharmacy claims that such compounded mixtures are safer or more effective than other hormone formulations, the FDA warned. They may not be mixed according to a licensed health-care professional's instructions, the agency said.
"Women should be cognizant that both products have similar potencies, similar biological action and similar side effects," Liu said. "There's no reason to think bio-identicals are superior. There are either anecdotal or testimonial claims that one is better than the other. We're swayed by that as human beings."
Here are some points the FDA says to keep in mind:
Visit the FDA for more on menopause and hormones.
SOURCES: James Liu, M.D., chairman, department of obstetrics and gynecology, MacDonald Women's Hospital, Case Medical Center, University Hospitals, Cleveland; Suzanne Steinbaum, D.O., director of Women and Heart Disease, Lenox Hill Hospital, New York City; Bio-Identicals: Sorting Myths from Facts, U.S. Food and Drug Administration