Does Chinese herbal medicine work for menstrual cramps?

Well, if you believe the results of a recent review by the Cochrane Collaboration, an international nonprofit organization that evaluates medical research, the answer would be yes.
But its new analysis of pooled data from 39 studies, which included 3,475 women, is difficult to interpret because many of the studies did not test Chinese herbs against placebos, harmless look-alikes. Moreover, because of methodological weaknesses, studies conducted in China, which many of these were, typically come up with positive findings, when more rigorous studies might not, said Ted Kaptchuk, an associate professor of medicine at Harvard Medical School who is also a practitioner of Chinese medicine.