Chinese herbal formula Xuefu Zhuyu oral liquid for primary dysmenorrhea: a multicenter randomized controlled trial

Objectives Primary dysmenorrhea (PD), affecting 50%−90% of women, significantly impacts quality of life. However, the need for treatment remains unmet because of side effects and insufficient efficacy. Xuefu Zhuyu (XFZY) oral liquid is a Chinese patent medicine widely used for PD in China, but high-quality evidence is lacking. Methods A multicenter double-blind, randomized, placebo-controlled trial was conducted among PD patients aged 18–35 years old. Participants were randomly assigned to receive either XFZY oral liquid or a matched placebo for 3 months. The primary outcome was the change in mean pain intensity as measured by VAS from baseline to the end of treatment. Secondary outcomes included quality of life, the Cox Menstrual Symptom Scale, change of pain duration, painkiller use, etc. Results Of 256 eligible participants, 129 received XFZY, and 127 received a placebo. There was no significant difference in the primary outcome between groups (adjusted mean difference: −0.18, 95% CI: −0.67 to 0.31, P = 0.463) in FAS analysis. However, the XFZY group had significantly lower rates of painkiller use (9.2% lower during the treatment period, 10.1% lower overall; P < 0.05) and consumed fewer painkillers ( P < 0.05) than the placebo group. Other secondary outcomes were not significantly different between the two groups. Adverse event incidence was similar between groups. Conclusions This trial did not demonstrate a benefit of the change in the mean pain intensity in treating PD with XFZY oral liquid. However, XFZY significantly reduced painkiller use and demonstrated good safety, suggesting its potential as an alternative analgesic for PD. Clinical trial registration https://www.chictr.org.cn/showproj.html?proj=44287 , identifier: ChiCTR1900026819.