Cai's gynecology cyclical therapy with stasis-clearing and meridian-warming method for primary dysmenorrhea: a randomized controlled trial.
Bowen Xu et al. (2026) · Frontiers in endocrinology
This open-label randomized trial at Shanghai East Hospital compared two approaches to primary dysmenorrhea (menstrual cramping without an underlying pelvic disease) in 80 women aged 15 to 46: a Traditional Chinese Medicine protocol called Cai's Gynecology Cyclical Therapy, paired with a specific formula called the Stasis-Clearing and Meridian-Warming Method, versus standard ibuprofen. The TCM approach is built on a century-old idea from a Shanghai medical lineage: that treatment should change across the four phases of the menstrual cycle rather than staying the same throughout. Forty women received ibuprofen (a common anti-inflammatory pain reliever) for two days during each period, while the other forty received herbal decoctions -- different formulas depending on the cycle phase -- for three full menstrual cycles. Researchers tracked pain on a 0-to-10 visual pain scale and a symptom-severity score, and checked whether pain returned in the month after treatment ended. People collecting the follow-up data did not know which treatment each woman had received. Both treatments worked well overall (97.5% of women improved in each group), but the pattern of improvement differed. Ibuprofen relieved pain faster in the first month, as expected for a direct pain reliever. The herbal treatment started more slowly but kept improving month after month, and by the third month the two treatments were statistically equivalent on both pain and symptom scores. The most striking difference came after treatment stopped: only about 13% of the herbal-treatment group had their pain return the following month, compared to about 90% of the ibuprofen group. No side effects were reported in either group throughout the study. The researchers suggest this gap in relapse rates may reflect a real difference in how the two approaches work -- ibuprofen blocks pain-causing chemicals only while it is being taken, whereas the herbal protocol may produce a more lasting change. However, because patients and treating doctors could not be kept unaware of which treatment they were giving or receiving (an inherent challenge when comparing herbal decoctions to a standard pill), and because the study involved one hospital and a single follow-up cycle, the authors call for larger, multi-site studies with longer follow-up to confirm these findings.