NEW YORK (Reuters Health) Jul 22 - An herbal remedy widely used in Japan to ease menopause symptoms failed to show the same benefits in a clinical trial of U.S. women, researchers report.
The study looked at the effects of keishi-bukuryo-gan, a mix of cinnamon bark, peach pit and several other botanicals that is also known as known as TU-025.
Long used in traditional Japanese medicine, the herbal remedy is now regulated as a prescription drug in Japan, where gynecologists commonly recommend it for treating hot flashes and other symptoms of menopause.
So researchers were interested in whether benefits would be seen in U.S. women as well.
The authors randomly assigned 178 postmenopausal women to take either keishi-bukuryo-gan tablets or a placebo every day for three months. Tokyo-based Tsumura & Company provided the herb and partially funded the study.
In the end, the researchers found that while women on the herb saw improvements in hot flashes, sleep problems and other symptoms, so did women on the placebo.
And there was no clear advantage of the herbal product, the team reported online June 28th in Menopause.
Hot flash frequency and severity dropped by a significant degree in 34% of the placebo group. The same was true of 40% of women taking 7.5 g of keishi-bukuryo-gan every day and 38% of those taking 12.5 g a day.
The differences among the three groups were not statistically significant, said Dr. Gregory A. Plotnikoff, who directs the Institute for Health and Healing at Abbott Northwestern Hospital in Minneapolis, and colleagues.
What's more, 20% of the women using keishi-bukuryo-gan reported diarrhea as a side effect. That was unexpected, Dr. Plotnikoff's team says.
In Japan, a decade of post-marketing surveillance of the product has suggested that side effects are rare.
Of more than 700,000 women who've used the herbal remedy, an estimated 0.004% have had an adverse event, the researchers note in their report.
It's not clear why this trial of U.S. women failed to show the benefits that have been seen in Japanese women. But the researchers point out that in Japan, keishi-bukuryo-gan is used as part of the traditional medicine system known as Kampo, which considers each individual patient's "constitution."
Based on that system, the researchers note, keishi-bukuryo-gan is best for women who normally tend to feel cold (when they're not having hot flashes or night sweats), and are deemed to have stagnant qi (pronounced "chee"). Qi is a concept in traditional Chinese and Japanese medicine that refers to the flow of energy through the body.
In this study, women were included if they'd been having frequent or severe hot flashes -- and not based on any constitutional factors.
Dr. Plotnikoff's team speculates that this could have something to do with the lack of benefit overall, and possibly the side effect of diarrhea seen in some women.
While keishi-bukuryo-gan is a prescription drug in Japan, it's available as an unregulated supplement in the U.S. -- generally as a capsule or a powder to make tea. The cost varies depending on the formulation and daily dose, but typically starts at about $30 for a one-month supply.