Use of bioidentical hormones—estrogen, progesterone, and testosterone derived from plants such as soy or yam—has grown rapidly over the last decade. But recent FDA rulings about claims for bioidentical hormone therapy (BHT) has made this one of the most controversial issues in women’s health.

The surge in bioidentical hormone use was driven by publication of the Women’s Health Initiative (WHI) in 2002, showing increased health risks for women on PremPro (a synthetic hormone). WHI showed a 26% increase in breast cancer; 29% for heart attack; 41% for stroke; 100% for blood clots; and over 100% for Alzheimer’s or dementia.

Following WHI, millions of women stopped HRT and had symptoms rebound. Others started on antidepressants, as Big Pharma positioned these drugs as HRT substitutes. Most of these women are not depressed, and by taking antidepressants they are exposed to a new set of potential side effects. Still others began exploring BHT, believing it to be safer than conventional HRT. Interest was fueled by Suzanne Somers’ books, Ageless, and The Sexy Years, in which the actress glowingly describes her experiences with BHT.

Bioidentical hormones are derived from natural plant sources, but they undergo chemical processing to make them identical in structure to human estrogen, testosterone, and progesterone. Synthetic hormones are intentionally different from naturally occurring hormones. Drug companies can’t patent bioidentical structures, so they invent synthetics like Premarin, Prempro, and Provera, which are patentable because they are structurally different from natural hormones.

Several branded versions of BHT are now available, generally in one-size-fits-all regimens: bioidentical estradiol in the form of Estrace, Estraderm, Estrasorb, Climara, Vivelle or Femring; and bioidentical progesterone, sold only as Prometrium. No company has yet put out a bio-identical estradiol-progesterone combination, so most women with intact uteri need two prescriptions (e.g., a weekly estradiol patch, and Prometrium pills taken nightly or cyclically).

Advocates of BHT contend it is more effective for symptom relief and safer than synthetic HRT. The great appeal is that BHT is “natural,” and can be better metabolized by the human body, minimizing side effects. Compounded BHT can be matched individually to each woman’s needs, which is impossible with mass-produced synthetic products. Patients can also avoid dyes and preservatives present in synthetic hormones. One disadvantage is that BHT may not be covered by third-party payers, so it is usually costlier to patients.

On the safety side, I have not found any studies proving that BHT products are inherently safer than conventional HRT. WHI assessed synthetic/equine-based HRT (Prempro), and we cannot draw any firm conclusions about BHT from WHI findings. It is wrong to assume, as some people do, that the health risks seen in WHI were due to the synthetic nature of the hormones or that BHT would have obviated that risk.

The North American Menopause Society recently published a position statement (Menopause, Vol. 15, No. 4, 2008) recognizing advantages and disadvantages of BHT, and recommending that BHT products carry a package insert identical to those in FDA approved HRT. NAMS maintains that for most women, synthetic HRT is appropriate, though for some, the benefits of BHT outweigh disadvantages.

In my practice, I’ve had the most success with an individualized approach. I begin with a thorough history and physical, including breast exam and mammogram, bone densitometry, lipid panel, hsCRP, fasting blood sugar, and sometimes, but not always, measures of hormones in blood, urine and/or saliva. I assess the risk of CVD, diabetes, cancer, and dementia.

Many women can restore hormone balance and obtain symptom relief without either synthetic or bioidentical HRT, using just nutritional supplements, diet/lifestyle changes, herbs (e.g., Black Cohosh), endocrine support such as thyroid and adrenal glandulars, and phytoestrogens.

For those with severe symptoms, or who are already on HRT, I may prescribe an individualized regimen of compounded BHT, almost always in the form of a cream (estrogen, progesterone, and often testosterone) to be applied to various places on the skin and sometimes vaginally. Occasionally, I will prescribe pills or sublingual tablets. I monitor carefully through regular follow-up and further testing. The goal is to get symptom relief at the lowest possible doses.

I don’t recommend any hormones—bioidentical or synthetic—be used long-term unless the patient is truly symptomatic, and then only with ongoing risk assessment. BHT should not be used indefinitely, as a “Fountain of Youth”.

The matter of HRT in women with a history of breast cancer is unresolved. Epidemiologic evidence is mixed, and there are no completed long-term RCTs. WHI shows a slightly increased breast cancer rate with estrogen/progestin use after 3 to 5 years. But estrogen alone for under 5 years had little impact. I generally avoid BHT in women who have had breast cancer, though there are exceptions. I will only prescribe it after we have thoroughly discussed the issues, and the patient can make a well-informed decision for herself.

As use of BHT has grown, so has regulatory scrutiny. In January, FDA ruled that pharmacies touting BHT as safer and more effective than conventional HRT are making false and misleading claims, and further, that pharmacies may not compound estriol without an investigational new drug authorization (see www.fda.gov/cder/pharmcomp/default.htm). The agency issued warning letters to seven large compounding pharmacies providing BHT.

The rulings are largely in response to a “citizen’s petition” filed in 2005 by Wyeth, maker of PremPro, which urged FDA to take action against pharmacies dispensing BHT. Wyeth’s request and FDA’s moves have met with intense opposition from health freedom groups.

In my view, pharmacies can avoid FDA actions simply by refraining from making claims. The decision to use hormones, whether synthetic or bioidentical, should be a matter between patient and physician. We, as practitioners, and our patients, ought to have freedom to choose from among all available, safe and effective options. I have found estriol to be a very effective treatment for atrophic vaginitis, and it should not require a new drug authorization.

So far, compounding pharmacies have not generally complied with FDA’s new rulings, and use of BHT continues undiminished. It remains to be seen whether federal authorities will take direct enforcement action.

Michael Traub, ND, DHANP, FABNO, past-president of the American Association of Naturopathic Physicians, practices on the Big Island of Hawaii. He is designing a study to compare the relative efficacy of an emulsified liquid vitamin D with a capsulated vitamin D. Interested parties may contact him at michaeltraub@earthlink.net.