Seven databases were comprehensively searched, namely, the English-language databases Cochrane Library, Web of Science, EMBASE, PubMed, and the Chinese-language databases Wanfang, VIP Information, CBM, and China National Knowledge Infrastructure (CNKI) from inception up to December 2024. Randomized controlled trials on the treatment of PD by warm decoction combined with acupuncture are retrieved from these databases. The retrieval method combines subject terms and free terms. Our retrieval strategy comprised three main components: clinical conditions (including pain, menstrual, menstrual pain, menstrual pains, pains, menstrual, dysmenorrhea, menstrual pain, painful menstruation, period pain, painful period, menstrual cramps, menstrual disorder, pelvic pain, and painful menstrual periods); interventions (Wenjing combined with acupuncture, electroacupuncture, manual acupuncture, warming needle, acupuncture therapy, needling, needles, needle therapy, and moxibustion treatment); and study types (RCT).

No retrieval filters or limits were applied. To identify redundant papers, researchers manually examined the reference summaries of the retrieved articles. The initial screening of articles, conducted independently by the first two authors (MZ and LXW), involved a thorough review of titles, abstracts, and full texts to substantiate the eligibility of the studies. Any uncertainties regarding inclusion were deliberated among the other authors (LWX and FHZ).

The inclusion criteria, based on the PICOS (patients, intervention, comparator, outcomes, and study design) framework, were pre-specified as: (1) Participants: patients diagnosed with dysmenorrhea of any age, case source, and disease duration and severity; (2) Intervention: Treatment with Wenjing decoction combined with Acupuncture; (3) Control method: Treatment with Western medicine; (4) Outcome measures with sufficient data: Effective rate; dysmenorrhea symptom score; serum PGF_2α and PGE2; uterine artery blood flow RI and PI, etc. (5) study type: RCT; and (6) availability of complete data in the literature and precise data in the experimental and control groups.

Exclusion criteria filtered out studies were (1) non-RCT, animal studies, case reports, conference proceedings, or literature reviews; (2) with ambiguous diagnostics; (3) of incomplete data or unavailable full-text; or (4) of duplicates.

Two independent reviewers (MZ and LXW) extracted the following data, such as the first author’s name, year of publication, study design, participants’ characteristics, specifics of Wenjing decoction combined with acupuncture and control intervention, and outcomes metrics. Disputes were resolved by a third reviewer (LXW).

Meanwhile, the quality assessment of the included studies was carried out by two independent reviewers (MZ and LXW) utilizing the Cochrane Collaboration’s Risk of Bias tool, and seven reviews were shared: (1) random sequence generation; (2) assign hidden schemes; (3) whether participants and intervention implementers were blinded; (4) blinding and attrition bias for outcome evaluation; and (5) whether the outcome data are complete; (6) selective reporting of research results; and (7) other sources of bias. Finally, three grades (low risk, unknown risk, and high risk) were evaluated according to the literature report. Any discrepancies were resolved through discussion with LXW.

We evaluated the quality of evidence for all primary outcomes using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. This systematic methodology assesses evidence certainty across five domains: (1) risk of bias (study limitations), (2) inconsistency (heterogeneity), (3) indirectness (generalizability), (4) imprecision (sample size and confidence intervals), and (5) publication bias. Randomized controlled trials initially start as high-quality evidence but may be downgraded based on deficiencies in these domains. Conversely, evidence may be strengthened for large effect sizes, dose–response gradients, or when residual confounding would likely reduce the observed effect. Two independent reviewers (MZ and LXW) conducted the GRADE assessments, with any discrepancies resolved through discussion with a third reviewer (LWX). The final evidence certainty was categorized into four levels: high (further research is improbable to change our confidence in the effect estimate), moderate (further research may have an important impact), low (further research is very likely to have an important impact), or very low (any effect estimate is very uncertain).

Use RevMan 5.4 software to conduct heterogeneity tests, draw forest plots, and funnel plots. For dichotomous variables, the relative risk (RR) is used to represent the effect index, and for continuous variables, the mean difference (MD) or standardized mean difference (SMD) is used to measure and represent the effect index. The chi-square test and I² statistic are used to judge the heterogeneity among studies. If the heterogeneity among studies has no statistical significance (p > 0.1 and I² < 50%), the fixed effects model is adopted; otherwise, the random effects model is used.

Sensitivity analysis is carried out by removing individual literatures one by one, and subgroup analysis is also used for heterogeneity testing. Publication bias is evaluated by drawing funnel plots.

Planned Subgroup Analyses and Meta-Regression: To investigate potential sources of heterogeneity, we pre-specified the following subgroup analyses if sufficient data were available (≥10 studies per subgroup):

We planned to use random-effects meta-regression to explore the association between these covariates and the effect size for the primary outcome (pain score).

A total of 168 relevant literature reports were retrieved from relevant databases, of which 168 were Chinese literature reports and 0 were English literature reports. After excluding duplicate literature reports and conducting a hierarchical selection process, a total of 11 literature reports were included for analysis, all of which were in Chinese. As shown in Figure 1.

In this study, a total of 11 literatures met the inclusion criteria (17–27), all of which were randomized controlled trials. The 11 studies included a total of 1,024 subjects, 512 in the experimental group and 512 in the control group. All study participants had the same baseline. The literature features are shown in Table 1.

The 11 literatures included in the study all mentioned the adoption of random research methods, 3 studies (19, 21, 23) used the envelope method for allocation and hiding, and 2 studies used the random number table method (18, 24), these five studies were judged to be low risk, and the rest did not describe the specific implementation method of randomization in the study. None of the included studies were designed for allocation concealment, blinding, or outcome evaluation. None of the studies had dropouts or loss to follow-up. The outcome indicators of the included studies were complete, and the reports were not omitted. The results reported in the studies were consistent with the design of the literature; all studies were compared at baseline and demonstrated comparability. In this study, RewMan 5.4 software was used to make percentage and quality assessment charts for the risk of bias in the included documents. The bias assessment of the included literature is shown in Figures 2, 3.

Eleven studies (17–27) all reported the clinical effectiveness rate of Wenjing decoction combined with acupuncture and moxibustion compared with Western medicine in the treatment of PD. A heterogeneity test was conducted, yielding I² = 71%, p < 0.00001, indicating that there is high heterogeneity among the studies, and heterogeneity needs to be searched. Through a sensitivity analysis of 11 documents, it was found that Fangjing (23) and Haixia (24) had a high impact on heterogeneity. After removing the two documents, there was no heterogeneity in the remaining nine documents (I² = 34%, p = 0.15). Therefore, a fixed effect model was used. Meta-analysis results showed that RR = 1.24, 95% CI: (1.06, 1.42), Z = 7.09, p < 0.00001, and the difference was statistically significant, indicating that the curative effect of Wenjing decoction combined with acupuncture and moxibustion in the treatment of primary dysmenorrhea is significantly better than that of Western medicine analgesics.

For specific situations, see the following forest plot (Figure 4).

A total of 4 studies (18–20, 24) reported pain scores for dysmenorrhea, and heterogeneity tests yielded I² = 99%, p < 0.00001, indicating that there was a large heterogeneity between the studies and that heterogeneity was required. Subgroup analysis was carried out according to the addition and subtraction of different prescriptions and acupuncture methods, and the sensitivity analysis was carried out by eliminating individual literatures one by one; no sources of heterogeneity were found, so a random-effects model was selected. The results of meta-analysis showed that MD = −4.13, 95% CI: [−6.42, −1.84], Z = 8.75, p < 0.05, the difference was statistically significant, The results showed that the pain score of Wenjing decoction combined with acupuncture in the treatment of primary dysmenorrhea was lower than that of the control group, and the difference was statistically significant, as shown in the following forest plot (Figure 5).

A total of three studies (24, 25, 27) reported serum PGF_2α, which was tested for heterogeneity, with I² = 99%, p < 0.00001, indicating that the heterogeneity among the studies was large, and heteroplasms should be tested. Subgroup analysis was performed according to different prescriptions and acupuncture methods, and sensitivity analysis was performed by excluding individual literatures one by one. No source of heterogeneity was found, so the random effects model was selected. Meta-analysis results showed that MD = −11.96, 95% CI: (−25.21, −1.28), Z = 1.77, p < 0.05. The difference is statistically significant, suggesting that the PGF_2α value of Wenjing decoction combined with acupuncture in the treatment of primary dysmenorrhea is lower than that of the control group, and the difference is statistically significant. See the following forest plot for specific conditions (Figure 6). The small sample sizes (median n = 40 per trial) and wide confidence intervals further limit the precision of these estimates.

There are three studies (18, 25, 27) that reported serum PGE₂. A heterogeneity test was conducted. A heterogeneity test was conducted, yielding I² = 63%, p = 0.07, suggesting that there is great heterogeneity among the studies and heterogeneity needs to be investigated. Subgroup analysis was performed according to different prescriptions and acupuncture methods, and sensitivity analysis was conducted by excluding individual literatures one by one. No source of heterogeneity was found. Therefore, the random effects model was selected. Meta-analysis results showed that MD = 5.9, 95% CI: (2.27, 9.52), Z = 3.19, p < 0.05, and the difference is statistically significant. It is suggested that the PGE₂ value of Wenjing decoction combined with acupuncture in the treatment of primary dysmenorrhea is higher than that of the control group. The situation is shown in the forest map below (Figure 7).

A total of two studies (17, 21) reported uterine artery blood flow RI. A heterogeneity test was performed, yielding I² = 18%, p = 0.27. Since there is no heterogeneity, the fixed effect model is used. Meta-analysis results show that MD = −0.09, 95% CI: (−0.12, −0.07), Z = 6.38, p < 0.00001. The difference is statistically significant, suggesting that Wenjing decoction combined with acupuncture can improve uterine artery RI blood flow and then reduce pain. The effect is better than that of Western medicine. See the following forest plot for specific conditions (see Figure 8).

A total of two studies reported uterine artery blood flow PI. A heterogeneity test was performed, yielding I² = 0%, p = 0.41. Since there is no heterogeneity, the fixed-effect model is used. Meta-analysis results show that MD = −0.39, 95% CI: (−0.44, −0.33), Z = 13.19, p < 0.00001. The difference is statistically significant, suggesting that Wenjing decoction, when combined with acupuncture, can improve uterine artery PI blood flow and thereby reduce pain. The effect is better than that of Western medicine. For specific conditions, see the forest plot shown in Figure 9.

Due to the limited number of studies per outcome (n < 10 for most), the planned meta-regression was not feasible. The insufficient number of studies precluded meaningful subgroup analysis.

Funnel plots were drawn for the pain score and PGF_2α, which had relatively large heterogeneity among the indicators of treating PD with Wenjing decoction combined with acupuncture and Western medicine, to conduct publication bias detection. The results showed that the symmetry of the distribution on both sides of the funnel plots was poor, indicating a potential publication bias in the study (Figures 10, 11). However, the scatter distributions of the funnel plots for the effective rate, PGE₂, uterine artery blood flow RI, and PI were basically symmetrical (Figures 12–15), suggesting that the possibility of publication bias was relatively small.

To assess the overall quality and strength of evidence for our primary outcomes, we conducted a Grading of Recommendations Assessment, Development and Evaluation (GRADE) evaluation (Table 2). The evidence certainty was rated as moderate for total effective rate and uterine artery blood flow parameters (RI and PI), where significant treatment effects were observed with acceptable consistency across studies. However, the evidence was downgraded to low certainty for pain scores and prostaglandin levels (PGF_2α and PGE_2α) due to substantial heterogeneity (I² > 60%) and methodological limitations in the included trials, including a lack of blinding and allocation concealment. Publication bias was suspected for pain-related outcomes based on funnel plot asymmetry. These GRADE assessments highlight both the potential benefits of acupuncture combined with Wenjing decoction and the need for more rigorous studies to strengthen the evidence base.

The certainty of evidence was downgraded to low for both pain scores and PGF_2α due to (1) substantial unexplained heterogeneity (I² > 90%); (2) high risk of bias in >50% studies (lack of blinding); (3) imprecision (total sample <400, optimal information size not met); and (4) suspected publication bias (funnel plot asymmetry).

The findings of this review, while promising, are derived from evidence of low-to-moderate certainty. Therefore, they should not yet be seen as justifying the routine replacement of first-line therapies. Instead, clinicians might consider the combination of acupuncture and Wenjing decoction in the following specific scenarios, always within a shared decision-making framework that acknowledges the current evidence limitations to the patient: (1) As an Adjunct to First-Line Therapy: For patients experiencing partial or inadequate relief from NSAIDs, adding this combination therapy could be a strategy to enhance pain control without solely increasing the NSAID dosage, potentially mitigating gastrointestinal side effects. (2) An Alternative for NSAID-Intolerant Patients: For individuals with contraindications to NSAIDs (e.g., peptic ulcer disease, renal impairment, or aspirin-exacerbated respiratory disease) or those who experience significant adverse effects, this approach may represent a viable non-pharmaceutical alternative. (3) An option for Patients with a Preference for Non-Pharmacological or TCM Approaches: For patients who actively seek integrative medicine options or have cultural preferences for TCM, this combination provides a structured treatment strategy that aligns with their values. However, clinicians should weigh these methodological concerns against the consistent direction of benefit across all studies. The observed effects may represent: (1) a true biological effect attenuated by measurement variability; (2) differential responses across PD subtypes; and (3) placebo effects amplified by unblinded designs. Future trials should standardize intervention protocols and stratify by pain etiology (e.g., primary vs. secondary dysmenorrhea) to reduce heterogeneity.

Our findings must be interpreted with caution due to: (1) Single-country evidence (China): May limit generalizability to other populations with different healthcare systems or cultural perceptions of acupuncture. (2) Unblinded designs: 92% (10/11) of trials lacked participant/practitioner blinding, potentially amplifying placebo effects. (3) Short-term interventions: Median treatment duration was 90 days (3 cycles), with no studies evaluating >6-month outcomes. (4) Placebo confounding: Combined therapy’s multi-modal nature (needling + herbs) may enhance non-specific effects versus single-modality controls. (5) Standardization issues: Heterogeneity in Wenjing decoction preparations (e.g., herbal sourcing and decoction methods) and acupuncture protocols.

There are some limitations in this study: (1) no double-blind method was used in the included studies, so the placebo effect could not be excluded; (2) the heterogeneity of the studies summarized by some outcome indicators is relatively large, which may be related to differences in acupuncture methods, point selection, and allocation, and dosage forms of Wenjing decoction. After subgroup analysis and sensitivity analysis, the source of heterogeneity is still not found, which affects the reliability of the end result; (3) Publication bias exists in some of the aggregated outcome studies, which may lead to overevaluation of efficacy; (4) The sample size of some studies is small, and the lack of multi-center and large clinical studies limits the generalization of results; (5) None of the studies carried out long-term follow-up, lack of evaluation of the long-term effect of the combination of Wenjing decoction and acupuncture in the treatment of primary dysmenorrhea.

In light of these substantial limitations, the promising point estimates derived from our meta-analysis should not be overinterpreted as robust evidence of clinical efficacy. The high heterogeneity, risk of bias, and methodological shortcomings preclude any firm clinical recommendations at this stage. Therefore, the clinical implications of our findings are necessarily tentative and hypothesis-generating rather than confirmatory.