naturalpostmenopausalhormones

"Natural" Postmenopausal Hormones: Not so natural, not so safe

When a landmark clinical trial reported in 2002 that the dangers of postmenopausal hormone drugs far outweighed the benefits, many more women turned to bioidentical or natural hormones. These products are widely portrayed in the media and on the Internet as safer than prescription hormone drugs like Prempro and Premarin for the relief of hot flashes and other menopausal symptoms. The idea that these products are safer or even natural is challenged in a paper by Adriane Fugh-Berman, MD, and Jenna Bythrow of the Complementary and Alternative Medicine Master’s Program, Georgetown University School of Medicine.

Sold as topical creams and tablets over the Internet and in health food stores, bioidentical hormones are actually synthetic versions of female hormones, including estriol, estrone, estradiol, progesterone, testosterone, DHEA, thyroxine and cortisol. In their paper published recently in the Journal of General Internal Medicine, Fugh-Berman and Bythrow contend that bioidentical is a meaningless term coined by a business that knows what sells.

Compounding Pharmacies

Many of these products are prepared by compounding pharmacies that convert prescription and non-prescription drugs into different formulations. For example, converting a drug manufactured in tablet form to a syrup for people who have difficulty swallowing pills or a pet-sized dose of a drug meant for humans. In the case of bioidentical hormones, the pharmacies are reformulating the standard prescription hormone drugs, usually in weaker doses.

Because compounding pharmacies are not manufacturing facilities, they are not required by the FDA to prove safety or effectiveness. “Compounding pharmacies have their place,” said Dr. Fugh-Berman in a telephone interview. “But [with bioidentical hormones] all these pharmacies are doing are buying hormones from Upjohn or some other drug company and following a recipe.”

“Bioidentical hormones are chemically identical to hormones produced by the body,” explained Dr. Fugh-Berman, but the term bioidentical is widely misunderstood. Most women surveyed at one compounding pharmacy either thought it meant “not man-made” or plant-derived; they no doubt got that impression from advertising and/or reading the product labels which often, for example, feature wild yams as the source of progesterone.

Bioidentical hormones are sometimes derived from starting materials of plants in a lab process, Dr. Fugh-Berman said, “but, you won’t get progesterone from eating a yam. Plants have precursors in them, but not actual progesterone.”

Because compounding pharmacies are unregulated, they can make unsubstantiated claims for their products. (Legislation has been introduced.) The most dangerous to Dr. Fugh-Berman are the claims that bioidentical hormones will prevent heart disease and breast cancer, as well as improve well-being—all of which have been discredited for standard hormone drugs in the landmark 2002 Women’s Health Initiative trial.

Also, women with an intact uterus must protect it against estrogen-induced endometrial cancer with the addition of progesterone. Studies show that many bioidentical progesterone products contain much weaker doses of the standard progesterone prescription drugs, so they do not provide the level of needed protection.

For the many women who do not want to hear her message and will continue taking bioidentical hormones no matter what, Dr. Fugh-Berman has this advice, “Now we know that [the conventional prescription] hormones help only symptoms—hot flashes and vaginal dryness—they don’t prevent disease,” she said, referring to the results of the 2002 Women’s Health Initiative trial. “So symptomatic women should take the lowest possible dose for the shortest period of time. Women without symptoms shouldn’t use either bioidentical or conventional hormones for disease prevention. Bioidentical hormones should be assumed to have the same risks as conventional hormone drugs and should carry the same warning labels.”

As for the standard claim that bioidentical hormones are natural, “Ironically, the estrogen in the best-selling hormone preparations Premarin, Prempro, and Premphase is derived from pregnant mare’s urine, an inarguably natural source.”