Streicher says the positive outcomes of the shorter studies are most likely coincidence. "The nature of perimenopause is that it's a roller coaster: the symptoms go up and down," she says, referring to the period of life surrounding menopause.
In 2007, the Office of Dietary Supplements at the National Institutes of Health convened a workshop to evaluate health concerns about black cohosh's potentially detrimental effects on liver and breast tissue. While their review did not find the herb particularly harmful, it didn't find it to be helpful, either.
"What you have is greedy entrepreneurs looking for a vulnerable group—and no one is more vulnerable than women with hot flashes," says Streicher. "I just hate to see women taken advantage of when there are things that really can help them."
Ginkgo. Ginkgo, also known as ginkgo biloba, is one of the world's most popular herbal supplements. It's said to improve memory and cognitive functioning, and even stave off Alzheimer's disease. With the population aging, small wonder it's experiencing booming use. Unfortunately, there's no solid evidence that it works.
Taken from the ginkgo leaf and usually sold in pills and teas, ginkgo has been used widely and studied repeatedly. Researchers' conclusions can be summed like this: Small studies have tended to paint the herb positively, while large studies have found no benefit. The most extensive trial, the Ginkgo Evaluation of Memory study, was funded by the National Center for Complementary and Alternative Medicine at the National Institutes of Health. Published in 2009, it examined whether ginkgo could lower the incidence of dementia and Alzheimer's disease in the elderly. The data was also subsequently used to see if ginkgo had slowed cognitive decline, inhibited dementia, reduced blood pressure, or prevented hypertension among the study's subjects. The herb struck out on every measure.
Like black cohosh, ginkgo is probably safe—as long as it's not consumed in seed form, which has been linked to seizures and even deaths. Nevertheless, the herb remains controversial among doctors. Those who oppose it do so mostly because it represents the success of an industry that's based on marketing and word of mouth rather than on science.
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How to Approach Herbal Supplements. In general, doctors say, dietary supplements have the potential to distract patients from seeking out evidence-based treatments, while squandering their resources. If you're looking to cut back your health spending, skip the trip to the supplement aisle—not the trip to see the doctor.
If you plan on giving any herbal remedy a try, look for the USP Verified mark on its label. That mark indicates that the product's manufacturer has voluntarily had it evaluated by the independent U.S. Pharmacopeia, a standards-setting authority that makes sure the product contains the ingredients listed on the label, doesn't contain harmful levels of particular contaminants, and complies with the FDA's Good Manufacturing Practices guidelines.
Mullin adds this advice: Begin taking one supplement at a time, so you'll know which is responsible if you have any adverse reactions. And, most importantly, tell your doctor what you're taking. "These are the basics: take one thing at a time, tell your doctor, stop if you're suspicious," he says. "Always do this under some kind of guidance."