Women taking hormone-replacement therapy got more worrisome news last month.
After years of concern about the long-term health risks of the therapy, a large clinical study concluded that health risks trump the health benefits of the most commonly prescribed estrogen-replacement drugs.
So where do the 6 million American women taking the drugs, and those considering replacement therapy, go from here?
For some women, the answer is so-called "bio-identical" estrogens, which are chemical replicas of hormones made by the human body.
Charlene Torrence, a 54-year-old office manager from Redmond, began taking bioidentical estrogens in March after suffering through two years of sleepless nights, mood swings and hot flashes. She was concerned about the cancer risk posed by conventional hormone-replacement therapy (HRT) and felt safer taking what is sometimes called a "natural" alternative.
"I've been 100 percent satisfied," she said. "Unless something comes out that says they're not good for me, I'm going to continue taking them."
Many medical professionals — both alternative and conventional — point out that no safety trials have been conducted on bioidentical HRT.
Comments Jane Guiltinan, a Seattle naturopath and dean of clinical affairs at Bastyr University, an alternative-medicine college in Kenmore: "I am not convinced yet that they are any safer than conventional hormones."
Below, we attempt to address what's known and what's not known about the safety and efficacy of bioidentical HRT and to answer some frequently asked questions for women considering the alternative.
Q: How is bioidentical HRT different from conventional HRT?
A: Bioidentical HRT uses estrogens that are exact chemical replicas of estrogens produced by the human body. Conventional HRT uses conjugated estrogens, so-called because they come from horse urine and are not chemically identical to human estrogens. Premarin, the drug whose safety was brought into question in last month's study, got its name from the phrase "pregnant mare urine."
Q: Does it completely replace all the hormones lost after menopause?
A: No. The human body makes dozens of types of estrogen; natural HRT replaces only three of them: estrone, estradiol and estriol. About 80 percent of estrogen circulating in the blood stream is estriol. The majority of the remaining 20 percent is estrone and estradiol, with other types of estrogens circulating in smaller amounts.
Premarin also has dozens of different types of estrogens, though these are horse estrogens and are not chemically identical to human estrogens.
Q: Where do the three estrogens in bioidentical HRT come from?
A: The giant Mexican yam, but that's just the starting point. Manufacturers start with a molecule from the yam and then chemically alter it until it's the same as human estriol, estrone or estradiol. Yams are used because they are cheap to grow and produce a molecule that's easy to convert to human estrogens. (The first birth-control pill had estrogen derived from yams, but it was not bioidentical.)
Q: Will eating yams reduce menopause symptoms?
A: No. The molecule in yams has no estrogen-like effects. It's only the starting point for the chemical process that produces bioidentical estrogens.
Q: Is bioidentical HRT the same as plant sources of estrogen, such as soy, red clover or flax seeds?
A: No. Some plants have chemical agents in them that have some estrogen-like effects in the human body, but are not bioidentical.
Q: How long has bioidentical HRT been available?
A: For about 20 years. Dr. Jonathan Wright, whose Renton clinic treats more than 10,000 women with natural HRT, was one of the first doctors to prescribe the treatment and has written several books about alternative medicine, including one on natural hormone-replacement therapy.
He remembers a woman coming into his office in 1982 asking for natural hormones. He prescribed Premarin.
"She said to me with a smile, 'Do I look like a horse? I want the same hormones I had before this mess of depression and hot flashes started, I want them back,' " Wright said.
He says that now more than 4,000 doctors and naturopaths nationwide prescribe the medication to hundreds of thousands of women. With last month's news, more women are seeking out information about natural HRT.
Q: Why is it sometimes called "natural" HRT?
A: The term "natural" is used pretty liberally in alternative menopause therapies and can mean different things. Plant sources of estrogen, like soy, are called "natural" because they occur in naturally growing plants.
Bioidentical estrogens are made in a chemical factory, but they're called "natural" because they're chemically the same as hormones in the human body. While yams and horse urine are both naturally occurring, Premarin is usually not called a natural estrogen.
Q: What are the risks and benefits of conventional HRT?
A: Last month's study showed increased risk for breast cancer, coronary heart disease, stroke and pulmonary embolism, and decreased risk of osteoporosis and colon cancer. HRT reduces menopause symptoms such as hot flashes, mood swings, depression and loss of libido.
Q: Does bioidentical HRT have the same risks?
A: Nobody really knows, since there have been no safety trials.
Bastyr's Guiltinan says that there are some theoretical reasons that bioidentical HRT should be safer than conventional HRT — it's made with molecules produced in the human body, whereas horse estrogens aren't — but these are only theories that haven't been tested.
Andrea Lacroix, an epidemiologist with the Fred Hutchinson Cancer Research Center in Seattle asks, "Why would we assume that they have all of the benefits and none of the risks without evidence?"
Some of conventional HRT's health risks were found only after two decades of extensive safety testing, says Gary Elmer, professor of medicinal chemistry at the University of Washington.
Renton's Wright says, "We cannot tell you that bioidentical hormones are perfectly safe. What we can tell a woman is that it's vastly safer to put in her body the same hormones that were in her body and in the body of all of her ancestors for hundreds of thousands of years than it is to put in horse hormones."
Q: Why haven't safety trials been done?
A: Seattle gynecologist and holistic herbal-medicine specialist Dr. Michael Greer said that because natural compounds can't be patented, there's no incentive for anyone to sink money into big clinical trials, like the one that found long-term risks of conventional HRT.
"You don't have the money to actually prove the point and get the word out," he said.
Wright has applied for grants to put together a clinical trial, but has not received funding.
Q: If they're not tested, how can they be sold?
A: Naturally occurring, non-narcotic compounds are not subject to FDA regulation, so they can be sold without going through the safety and efficacy trials required of other drugs.
Wright says, "One can say these are approved by nature, rather than approved by the FDA."
Q: Is a prescription required?
A: Yes. A prescription from a doctor, nurse practitioner or naturopath is needed.
Prescriptions for bioidentical estrogens are filled at compounding pharmacies — pharmacies that mix drugs from the basic estrogen ingredients into pills, creams, liquid drops or another mode of delivery.
Compounding pharmacies make a mixture called "biest" that is 80 percent estriol and 20 percent estradiol. Another mixture, "triest," has 80 percent estriol and 10 percent of each of the other two major estrogens.
Q: Are "tailor-made" bioidentical estrogens available?
A: Because each prescription is hand-mixed, dosage can be varied from patient to patient. Greer and Wright both measure a woman's hormone levels and then give patient-specific mixing instructions to a compounding pharmacist.
Guiltinan doesn't tailor-make doses because she says not enough is known to effectively fine-tune the treatment.
"I think we're making some guesses about what's optimal and what's needed and what we want in a woman's body," she says.
Q: Do insurance plans cover bioidentical HRT?
A: Most insurance plans won't. Patients should contact their insurance companies directly to find out.
Q: Who should take natural HRT?
A: Wright says a woman needs to balance the risks of any replacement therapy with the discomfort caused by menopause symptoms and her risk for longer-term health problems.
Guiltinan's advice is, "If you don't need hormones of any kind — bioidentical or not — don't take them."
Eran Karmon: 206-464-2155 or firstname.lastname@example.org.