Evaluation of Wet Cupping Therapy: Systematic Review of Randomized Clinical Trials

Background: Wet cupping is a widely used traditional therapy in many countries, which justifies a continuous scientific evaluation of its efficacy and safety. Objectives: To perform a systematic review to critically evaluate and update the available evidence of wet cupping in traditional and complementary medicine. Methods: Ten electronic databases were searched from their inceptions to February 2016. Included studies were randomized clinical trials (RCTs) that evaluated wet cupping against any type of control interventions in patients with any clinical condition, as well as healthy individuals. Cochrane risk of bias tool was used to appraise the included RCTs. Results: Fourteen RCTs met the eligibility criteria. The included studies evaluated the following clinical conditions: nonspecific low back pain (NSLBP), hypertension, brachialgia, carpal tunnel syndrome (CTS), chronic neck pain, metabolic syndrome, migraine headaches, oxygen saturation in smokers with chronic obstructive pulmonary disease (COPD), and oral and genital ulcers due to Behçet disease. Two RCTs evaluated physiologic and biochemical parameters of healthy individuals. Overall, 9 RCTs favored wet cupping over various control interventions in NSLBP ( n = 2), hypertension ( n = 1), brachialgia ( n = 1), CTS ( n = 1), chronic neck pain ( n = 2), oxygen saturation in smokers with COPD ( n = 1), and oral and genital ulcers due to Behçet disease ( n = 1). Five RCTs showed no statistically significant between-group differences: NSLBP ( n = 1), metabolic syndrome ( n = 1), migraine headaches ( n = 1), and physiologic and biochemical parameters of healthy individuals ( n = 2). Included RCTs had a variable risk of bias across all domains and suffered methodologic limitations. Conclusions: There is a promising evidence in favor of the use of wet cupping for musculoskeletal pain, specifically NSLBP, neck pain, CTS, and brachialgia. Better-quality trials are needed to generate solid evidence and firmly inform policy makers.