Clinical research evidence of cupping therapy in China: a systematic literature review

This systematic review represents the first comprehensive study of the clinical evidence for cupping therapy in China, analyzing five decades of research between 1959 and 2008. The researchers identified 550 clinical studies through a systematic search in six databases, including 73 randomized controlled trials, 22 controlled clinical studies, 373 case series, and 82 case reports. The methodology involved systematic searches in Chinese databases (CNKI, VIP, Wan Fang, CBM) and international ones (PubMed, Cochrane), with comprehensive inclusion criteria for all types of clinical studies on cupping therapy. The results show significant growth in the number of publications, especially randomized trials in recent decades, with more than half published between 2006-2008.

Wet cupping was the most commonly used modality (58% of studies), followed by dry cupping (18.2%) and sliding cupping (8.7%). More than 50 different conditions were treated, the main ones being: pain (70 studies), herpes zoster (59 studies), cough/asthma (39 studies), acne (29 studies), and common cold (24 studies). Twelve of the top 20 conditions were related to pain, including chronic muscle pain, generalized pain, infectious pain, and neuralgia. Methodological quality assessment of randomized trials revealed significant limitations: no study was classified as low risk of bias, with 78.1% presenting high risk.

Problems included lack of sample size calculation, inadequate description of randomization, absence of allocation concealment, and insufficient blinding. Only 15 trials described randomization procedures and three mentioned blinding. Most (69.9%) used composite outcome measures with subjective classifications (cured, very effective, effective, ineffective), making international interpretation difficult. Meta-analyses specific to herpes zoster showed benefits of wet cupping compared with medications (RR 2.49 for cure, 95% CI 1.91-3.24), and for fibromyalgia demonstrated pain improvement when combined with acupuncture.

Importantly, no serious adverse effects were reported in the trials, suggesting a favorable safety profile based on prolonged clinical use. The clinical implications point to promising therapeutic potential, especially for painful conditions, herpes zoster, and respiratory symptoms. However, current evidence is insufficient for definitive clinical recommendations due to the predominantly low methodological quality. Limitations include significant heterogeneity in study designs, populations, interventions, and outcome measures, as well as geographic concentration in China, limiting generalizability.

Future studies need greater methodological rigor, larger samples, protocol standardization, and adherence to international guidelines such as CONSORT and STRICTA to adequately report the details of cupping therapy.