Using herbs for menstrual cramps is a traditional Chinese remedy. Si Wu Tang, or Four Agents Decoction, is an eight-hundred year old formula that may bring relief when used long term. In Chinese medical herbal formulations consist of at least four different herbs.
Decoction is a method of extracting the essential oils or organic compounds from medicinal plants. Usually the protocol calls for mashing and then boiling the plant tissue to refine the desired compounds from the plant although chemicals may also be used to dissolve the plant. The use of this formulation of herbs for menstrual cramps was studied extensively in Taiwan. A double-blind placebo-controlled study was conducted at a teaching hospital in Taipei in which 78 women, who reported painful periods, were clinically diagnosed as being dysmenorrheal. The patients were given 15 capsules of Si Wu Tang per day for five days at the inception of their menstrual periods or onset of pain. Each woman kept an online chart of her perceived pain for the five day drug protocol. Maximum single-day pain and peak-pain were charted. The group taking Si Wu Tang had decreases in peak-pain and overall pain, which was the average pain intensity for the five days. The control group taking a placebo reported pain increases in both categories however, the data was not statistically significant. The results of the evaluation of pain during the first menstrual cycle after the initial study did show statistically significant differences in both peak-pain and overall-pain. This was an unexpected result. The use of herbs for menstrual pain warrants further examination. The study concluded no significant pain reduction in the first menstrual cycle but benefit from the treatment in subsequent cycles indicates that prolonged usage might be necessary to obtain meaningful relief. No detrimental side effects were observed in either group of patients and there is no indication that extended usage of Si Wu Tang is harmful.