‘Natural’ Is No Guarantee
Like most other middle-aged women, Nancy Smith heard the news last month that a commonly prescribed hormone replacement regimen could increase the risk of heart attacks, strokes and breast cancer.
But the Agoura Hills woman, 49, wasn’t sure what the Women’s Health Initiative study, which tested a synthetic estrogen-progestin pill called Prempro, meant for her personally. After all, she doesn’t take Prempro.
“This study was on the one-drug combination,” says Smith, a veterinarian. “What about everything else women take?”
Smith is among a growing group of women who take so-called natural estrogen and progesterone, which come from plant sources and are chemically identical to the hormones women make. “Natural” refers to the substance’s chemical composition, not its source.
Natural hormones have long been touted by alternative health practitioners and some Internet-based pharmacies to be safer and easier to tolerate than hormones made by drug companies and sold under names like Premarin and Prempro. More mainstream doctors are also recommending natural hormones, which are typically dispensed through compounding pharmacies. These pharmacies blend and package hormones in specific formulations ordered by doctors for individual patients.
Even some drug companies have developed brand-name products touted as natural because they contain one type of estrogen identical to what women’s bodies naturally produce.
And, in light of the recent findings, other doctors and women are wondering if natural hormones are a safer alternative.
The answer is that no one knows.
“Unfortunately, we know less about those products than we do about the ones in the trial,” says Dr. Elizabeth Barrett-Connor, a women’s health researcher at UC San Diego. “There is no safety data. There is no efficacy data. They might be preferable. They might be worse.”
Divergent Effects
There are clearly differences, however, in the way various hormone products are made, raising questions about whether they might have divergent effects in women.
The estrogen in Prempro and Premarin is derived from the urine of pregnant mares and contains equine estrogens and estrone, a form of estrogen natural in women.
Many women taking hormone therapy also take a progestin, a chemical that is synthesized to mimic a woman’s progesterone, because taking estrogen alone increases the risk of developing uterine cancer.
Natural estrogen and progesterone, in contrast, are made from plants, such as wild yams and soy, and are chemically identical to the hormones produced in women’s bodies. The natural estrogens--estradiol, estrone and estriol--are available in compounded formulations called triple natural estrogen (TriEst) or dual natural estrogen (BiEst). Natural progesterone is also available in a compounded formulation.
Some drug companies also make so-called natural estrogen products, such as Estrace, a pill, and Estraderm, a skin patch. But those products contain only estradiol.
Both traditional and natural estrogens mimic what a woman’s body makes and begins to lose during menopause. And some people say the natural hormones do a better job of that--not only because of their chemical structure but because the doses are typically lower.
“Most side effects from hormone therapy are related to doses. And the doses [made by drug companies] are just plain too strong for most women,” says Dr. Jay S. Cohen, a San Diego doctor and author of the book “Over Dose: The Case Against the Drug Companies.”
Compounding pharmacies can also package natural hormones as pills, creams, gels, suppositories or drops--which may improve how women absorb and metabolize them.
Difference in Delivery
There may be some theoretical basis for believing that the way hormones are taken can make a difference, says Dr. Richard King, a menopause expert in Gainesville, Fla. King says he prefers to prescribe an estrogen patch, so that the hormone bypasses the liver and goes directly into the bloodstream--possibly making it safer.
He also prescribes a natural progesterone called micronized progesterone that is made from yams. Micronized means the hormone is finely ground and is more easily absorbed by the body. Micronized progesterone synthesized from yams can also be ordered by prescription from compounding pharmacies and is available in a brand-name product called Prometrium.
But to think that natural hormones are a “safe” alternative to the hormones used in the Women’s Health Initiative study is too simplistic, many experts say.
“We’re hearing that ... ‘If you only get the product right, hormone therapy will work beautifully,’ ” says Dr. Maida Taylor, an associate clinical professor at UC San Francisco who has studied the issue. “But that is extremely unlikely. There is no reason to believe these will be safer.”
Compounded natural hormones may take longer to resolve menopausal symptoms, experts say. And compounded hormones, if not carefully constructed, can vary from batch to batch in their potency.
Women who switch from the traditional hormones to natural hormones should not be told that they are receiving a much different product, Taylor adds. “It’s very easy to make claims that something is better. But it’s very hard to do quality research,” she says.
It’s unlikely studies will be done to shed light on how different doses and formulations of estrogen and progesterone act. Since natural hormones cannot be patented--and accordingly, drug companies can’t make huge profits from them--there is little incentive for anyone to test them.
