A key researcher on the Women's Health Initiative (WHI) says she is disturbed at the major increase in women's use of "bio-identical hormones" in the wake of the WHI data showing safety problems with manufactured hormones.

There are not much data on what gynecologists and women are doing about menopausal symptoms now, Margery Gass, MD, principal investigator at the Cincinnati WHI site, told the February 28–March 1 meeting on the study at the National Institutes of Health.

But evidence from communities and from gynecological meetings shows that, in addition to strategies such as using the manufactured hormones at lower doses and for shorter periods, there's been a major increase in the use of bioidentical hormones mixed at compounding pharmacies, says Gass. "The implication being that they are being tailored to the individual woman."

Gass says she sees strong marketing efforts supporting these substances: "We see symposia being offered on bioidentical hormones that are implying that these are somehow safer and more effective than the pharmaceutical products. And there really are no outcome data to support these claims."

She also pointed to research suggesting that even women's own estrogen levels may be associated with higher levels of breast cancer or stroke, saying those findings, "are not really assuring us that these are going to be a lot safer than other estrogens that have been produced by pharmaceutical companies."