Dangguijagyag-san for primary dysmenorrhea: A PRISMA-compliant systematic review and meta-analysis of randomized-controlled trials.

The short version

This systematic review and meta-analysis pooled 14 randomized controlled trials (1,215 women, mostly from China with one from Japan) exploring whether Dangguijagyag-san (DJS) - a traditional East Asian herbal formula also called Danggui Shaoyao San - helps primary dysmenorrhea (PD), the cramping menstrual pain that occurs without an underlying pelvic disease. PD is common, estimated to affect 16-91% of women of reproductive age, and is driven by elevated uterine prostaglandins causing muscle spasm; standard NSAID and hormonal treatments carry gastrointestinal and other side-effect risks, which is part of why researchers keep examining herbal alternatives. The review followed a pre-registered protocol and searched eight medical databases through April 2019. The included trials compared DJS - most often prepared as a decoction (a boiled herbal liquid), given over roughly three menstrual cycles - against NSAIDs (5 trials), a placebo (1 trial), other herbal formulas (6 trials), or NSAIDs with moxibustion added to DJS (2 trials). The main outcome tracked was the total effective rate, a practitioner-judged measure of symptom improvement, alongside pain scores on a visual analogue scale in some trials. Pooled results favored DJS across every comparison. Against NSAIDs, DJS produced a higher effective rate (relative risk 1.16, meaning about 16% more improvement events, 95% confidence interval 1.08-1.24, with no meaningful variation between trials). Against placebo, DJS reduced pain scores and cut how often women needed rescue pain medication during their period. Against other herbal formulas, DJS again showed a higher effective rate (RR 1.24), an advantage that held up most consistently when DJS was prepared as a decoction rather than a granule or capsule. Adding moxibustion (heated-herb therapy at acupuncture points) to DJS outperformed NSAIDs alone (RR 1.47). Side effects were reported in only a handful of trials and were mostly mild digestive complaints, less frequent in the DJS groups than the NSAID groups. The review's authors rated the overall certainty of this evidence as moderate to low: most trials did not clearly describe how they randomized or concealed group assignment, could not blind participants to which herbal or drug treatment they were taking, and were often small (many under 100 participants), all conducted in East Asia. The findings do not establish how DJS performs in other populations or over longer treatment periods, and the authors call for larger, more rigorously designed trials to confirm the effect.

Key findings

• A meta-analysis pooling 14 randomized trials and 1,215 women found that the traditional herbal formula Dangguijagyag-san (also called Danggui Shaoyao San) improved primary dysmenorrhea (menstrual pain without an underlying pelvic disease) more than common NSAID pain relievers.
• Dangguijagyag-san also outperformed a placebo in reducing pain scores and reducing how often rescue pain medication was needed during menstruation.
• When Dangguijagyag-san was combined with moxibustion (a heat therapy applied at acupuncture points), it outperformed NSAIDs alone.
• Side effects were uncommon and generally mild digestive complaints, occurring less often in the herbal-treatment groups than in the NSAID comparison groups.
• The authors rated the overall certainty of the evidence as moderate to low because most of the 14 trials had unclear randomization methods, lacked blinding, and were conducted only in East Asia with relatively small groups of participants.

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