Updated evidence on the effectiveness of cupping therapy for pain relief: a systematic review and meta-analysis of randomized controlled trials

This systematic review and meta-analysis represents the most comprehensive evaluation of cupping therapy for the treatment of pain conducted to date. The researchers analyzed 72 randomized clinical studies involving 5,720 participants, a significant update of a prior review that included only 16 studies. The research investigated the efficacy of cupping therapy in treating acute and chronic painful conditions, including herpes zoster (20 studies), low back pain (14 studies), neck pain (9 studies), and osteoarthritis (9 studies). The methodology was rigorous, following PRISMA guidelines and registered in PROSPERO.

The researchers searched seven databases, including Chinese and international sources, covering publications from January 2014 to January 2023. Two independent reviewers extracted the data and assessed risk of bias using the Cochrane RoB 2.0 tool. Statistical analysis was conducted using a random-effects model, with meta-analyses performed when statistical heterogeneity was acceptable (I² ≤ 75%). The results showed that cupping therapy, whether alone or combined with other treatments, demonstrated consistent benefits in pain reduction.

On the visual analog scale, reductions ranged from 0.16 to 7.0 cm, with clinically significant differences. The cure rate increased on average by 20% in the cupping groups. Particularly notable was the subgroup analysis showing greater efficacy of cupping therapy for acute pain compared with chronic pain. The most commonly used modality was wet cupping (56.25% of studies), especially for herpes zoster.

The study found low-quality evidence suggesting that cupping therapy may improve quality of life, measured by the SF-36, with an increase of 4.78 points on the physical component. Sleep quality also showed significant improvements in two studies. An important safety finding: the incidence of adverse events was significantly lower in the cupping therapy groups compared with controls (RR 0.11), with only isolated cases of dizziness after wet cupping and mild skin lesions. The main limitation was that all 72 studies were classified as having high risk of bias, mainly due to methodological issues such as lack of adequate blinding, inadequately reported randomization, and possible publication bias.

Most studies (86%) were conducted in China and published in Chinese, which may limit the generalizability of the results. Despite the methodological limitations, this review provides substantial evidence that cupping therapy may be a valuable therapeutic option for pain management. The authors suggest that different treatment protocols can be developed for specific conditions, optimizing point selection, cup retention time, and type of cup used. For future research, they recommend studies with greater methodological rigor, adequate samples, appropriate randomization, and possible use of sham controls for blinding.