Cupping therapy is not considered scientifically proven by mainstream medical standards. There is some evidence it may help reduce pain, but the National Institutes of Health describes most cupping research as low quality and says the evidence for pain relief “isn’t very strong.” For other conditions, there simply isn’t enough rigorous research to draw conclusions.
That said, “not proven” doesn’t mean “disproven.” A growing body of studies shows real physiological changes happening under the cups, and some clinical trials report meaningful pain reduction. The picture is more nuanced than a simple yes or no.
What Cupping Actually Does to Your Body
Cupping creates negative pressure on the skin, and the body responds in measurable ways. Blood vessels in the treated area dilate as the body releases signaling molecules like adenosine, noradrenaline, and histamine. This increases local blood circulation, which has been confirmed across multiple studies. The suction also stimulates the autonomic nervous system, your body’s behind-the-scenes regulator of heart rate, digestion, and blood flow.
One leading explanation for how cupping works is called the nitric oxide theory. Nitric oxide is a molecule your body naturally produces to relax blood vessels and improve circulation. Cupping appears to trigger its release, which could explain why muscles relax and blood flow increases in the treated area. At the tissue level, researchers have observed improved microcirculation, faster capillary repair, and the growth of new small blood vessels in cupped regions.
For pain specifically, cupping may work through a gate-control mechanism. The pressure and mild discomfort from the cup essentially compete with pain signals traveling to the brain, temporarily reducing how much pain you perceive. Think of it like rubbing a spot after you bump it. The new sensation partially blocks the pain signal.
The Evidence for Pain Relief
Pain is where cupping has the most clinical data, particularly for chronic back pain. A systematic review and meta-analysis published in Revista Latino-Americana de Enfermagem pooled results from multiple trials and found that cupping therapy produced a statistically significant reduction in pain intensity compared to control groups (p = 0.001). On a standard pain scale, the average reduction was about 1.6 points, which is noticeable in daily life.
However, that same analysis flagged moderate to high variability between studies, meaning results were inconsistent from one trial to the next. Some studies showed large effects, others modest ones. This kind of inconsistency is a red flag in evidence-based medicine because it suggests the results may depend heavily on how the study was designed, who participated, or how cupping was applied.
In rheumatic conditions, wet cupping (which involves small skin punctures before applying the cup) has shown some promise. One study found it significantly reduced both pain and laboratory markers of rheumatoid arthritis activity. Another trial tested wet cupping for gouty arthritis and reported benefits. But these studies tend to be small, and many combine cupping with other treatments like herbal medicine or conventional drugs, making it hard to isolate cupping’s specific contribution.
The Placebo Problem
The biggest challenge in cupping research is designing a convincing placebo. You can feel a cup pulling on your skin, so how do you create a fake version that fools participants? Researchers developed a sham cupping device with a tiny 0.2mm hole that prevents suction from building up. The cup sticks to the skin with adhesive instead of vacuum pressure.
In a validation study with 34 participants, the sham device performed reasonably well as a blinding tool. About 76% of people in the sham group still felt some kind of sensation (pressing, inflating, squeezing), compared to 88% in the real cupping group. When asked to guess which treatment they received, 59% of sham recipients and 41% of real cupping recipients said they had no idea. The main detectable difference was pressure intensity: real cupping scored about 49 out of 100 on a sensation scale, while sham scored about 33.
This matters because many cupping trials don’t use sham controls at all. They compare cupping to no treatment or to a completely different therapy, which makes it impossible to separate the physical effects of cupping from the psychological effects of lying still, receiving hands-on care, and believing a treatment will help. Those psychological effects are real and can produce genuine pain relief, but they don’t tell us whether the suction itself is doing something unique.
Measurable Changes Beyond Pain
Some researchers have looked at blood markers to see if cupping changes anything at the cellular level. In a study of patients with acute herpes zoster (shingles), cupping combined with herbal compresses shifted the balance of immune signaling molecules. Specifically, levels of a pain-related compound called substance P dropped after treatment, while markers associated with a more effective immune response increased. These changes were statistically significant and occurred alongside improvements in pain scores and sleep quality.
The catch: this study used cupping alongside herbal treatment, so it’s unclear how much credit cupping deserves on its own. This is a recurring issue in the literature.
Cupping for Athletic Recovery
Cupping gained mainstream visibility when Olympic swimmers appeared with circular bruises during the 2016 Games. Athletes use it primarily to reduce muscle soreness and stiffness after intense training. Research confirms that cupping can decrease muscle stiffness when applied at appropriate pressures and durations, and some evidence supports improved range of motion in people with musculoskeletal tightness.
A study examining the triceps muscle found that cupping’s effect on stiffness varied depending on how long the cups stayed on and how much pressure was applied. This suggests it’s not a one-size-fits-all technique. But large, well-controlled trials specifically measuring athletic recovery outcomes like delayed-onset muscle soreness remain limited. Most of the evidence in this area comes from small studies or extrapolation from pain research.
Dry Cupping vs. Wet Cupping
Dry cupping uses suction alone. Wet cupping (known as hijama in Islamic medical tradition) adds a step: the practitioner makes small superficial incisions in the skin, then applies cups to draw out a small amount of blood. The two types show up in different research contexts.
Dry cupping is studied primarily for localized musculoskeletal problems like knee osteoarthritis and back pain, where improving blood flow and reducing muscle tension are the main goals. Wet cupping appears more often in studies targeting systemic conditions like rheumatoid arthritis, gout, and skin disorders like psoriasis and scleroderma, where researchers theorize the controlled blood removal may help clear inflammatory substances or modulate immune function.
The evidence for wet cupping influencing immune markers is intriguing but preliminary. Some studies report that it can reduce rheumatoid factor levels beyond what conventional therapy achieves alone, and there’s early data suggesting it modulates natural killer cell activity. These findings need replication in larger, better-designed trials before they carry much weight.
Safety and Side Effects
Cupping is generally considered low-risk when performed by a trained practitioner. The most common side effects are circular bruises (which typically fade within a week or two), mild pain during treatment, and occasional small blood blisters. In clinical trials of wet cupping for skin conditions, adverse events were relatively rare and included minor bruising and temporary pain at the cupping site. Interestingly, one systematic review found that wet cupping groups actually had fewer adverse events than comparison treatment groups.
Wet cupping carries additional risks because it breaks the skin. Infection is possible if equipment isn’t properly sterilized. People taking blood-thinning medications, those with bleeding disorders, and anyone with fragile or damaged skin in the treatment area should be cautious. Cupping over varicose veins or inflamed skin is also discouraged.
Where the Evidence Stands
The honest summary is that cupping produces real, measurable physiological changes (increased blood flow, reduced muscle stiffness, shifts in inflammatory markers) but the clinical evidence showing it reliably treats specific conditions remains weak by conventional standards. Most trials are small, many lack proper sham controls, and the ones that do exist show inconsistent results. The NIH classifies cupping as complementary rather than a substitute for conventional treatment, which reflects its current scientific standing: possibly helpful, not yet proven, and unlikely to cause harm when done correctly.