Menstrual Pain

Four Agents Decoction (Si Wu Tang), a type of Chinese medicine, may help reduce menstrual pain when used long-term, a new study suggests.

Researchers from the National Health Research Institutes in Taiwan found that the 800-year-old formula does not significantly reduce menstrual pain after three cycles of treatment; however, a beneficial effect may be present after a longer treatment.

Scientists explained that most traditional Chinese herbal formulas consist of at least four herbs. Four-Agents-Decoction is a documented formula containing four herbs and has been widely used to relieve menstrual discomfort in Taiwan. However, no specific effect had been systematically evaluated.

The randomized, double-blind, placebo-controlled, pilot clinical trial was conducted in an ad hoc clinic setting at a teaching hospital in Taipei, Taiwan. Seventy-eight young women with dysmenorrhea (painful periods) were enrolled after 326 women with self-reported menstrual discomfort in the Taipei metropolitan area of Taiwan were screened by a questionnaire and subsequently diagnosed by two gynecologists concurrently with pelvic ultrasonography.

Researchers administered a dosage of 15 odorless capsules daily for five days starting from the onset of bleeding or pain. The dosage regimen and treatment length used in the study were not associated with adverse reactions.

Study outcome was pain intensity measured by using an unmarked horizontal visual analog pain scale in an online daily diary submitted directly by the participants for five days starting from the onset of bleeding or pain of each menstrual cycle.

Overall-pain was the average pain intensity among days in pain and peak-pain was the maximal single-day pain intensity. At the end of treatment, both the overall-pain and peak-pain decreased in the Four-Agents-Decoction (Si Wu Tang) group and increased in the placebo group; however, the differences between the two groups were not statistically significant. The trends persisted to follow-up phase.

Statistically significant differences in both peak-pain and overall-pain appeared in the first follow-up cycle, at which the reduced peak-pain in the Four-Agents-Decoction (Si Wu Tang) group did not differ significantly by treatment length. However, the reduced peak-pain did differ among women treated for four menstrual cycles. There was no difference in adverse symptoms between the Four-Agents-Decoction (Si Wu Tang) and placebo groups.

The study authors concluded that Four-Agents-Decoction therapy showed no statistically significant difference in reducing menstrual pain intensity of primary dysmenorrhoea at the end of treatment. The finding of statistically significant pain-reducing effect in the first follow-up cycle was unexpected and warrants further study. Researchers recommended a larger similar trial among primary dysmenorrheic young women with a longer treatment phase and multiple batched study products to determine the definitive efficacy of this historically documented formula.

Integrative therapies with good scientific evidence in the treatment of painful menstruation and related conditions include calcium, sage and soy.

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