If you watched the Summer Olympics in Rio this past August, you undoubtedly saw quite a few high-profile athletes—most famously Michael Phelps—sporting large purple circles on their backs, shoulders, and other body parts, the result of “cupping.” We have since received inquiries from readers asking if this treatment really has healing power and improves sports performance. Obviously some Olympians (and many other people) think it does—but the evidence behind it is dubious.
Though there are several ways to do it, cupping involves creating a suction effect on the skin through the use of special cups (usually made of glass but sometimes plastic, rubber, clay, or bamboo) that are placed on the targeted area. This is said to promote circulation and draw out “stagnant” toxins and other harmful substances, and relieve musculoskeletal pain, among other supposed benefits. One way to create the suction is by lighting a flame (such as of an alcohol-doused piece of cotton) in the cup, and then, as the flame goes out, quickly placing the inverted cup on the skin. Another method involves vacuuming out the air in the cup with a pump. In wet (blood) cupping, the skin is pricked first. Typically, about 5 to 8 cups (or sometimes more), ranging from 1 to 2 inches in size, are applied and left on the skin for anywhere from 5 to 15 minutes.
A part of traditional Chinese medicine for thousands of years, cupping is increasingly used by acupuncturists, physical therapists, massage therapists, athletic trainers, and other health care practitioners in the West. It was reportedly done originally to draw out poisons from insect bites and to drain wounds, but now it’s touted as a seeming cure-all. For instance, the International Cupping Therapy Association maintains that “a huge number of conditions respond positively to cupping”—from asthma, colds, digestive disorders, and jaw pain (temporomandibular joint disorders) to menopause symptoms, cellulite, and vertigo. Athletes say it enhances muscle endurance and agility, prevents injuries, and speeds recovery from muscle fatigue.
What the research shows
Several study reviews have attempted to evaluate the effects of cupping, particularly for such conditions as low back pain, knee arthritis, headaches, and shingles. Some of the findings seem positive. For instance, a review of 16 trials, published in the Journal of Traditional Chinese Medical Sciences in 2014, found “at least moderate evidence that cupping is more efficacious than no treatment or other treatments (such as heat therapy, usual care, and conventional medications) in reducing pain over the short term.”
But as with acupuncture and many other alternative therapies, the studies overall are of poor quality and have had mixed results. Among the many problems, most studies don’t include proper control groups and thus cannot rule out a placebo effect. And when there is a placebo comparison group, participants and practitioners cannot easily be “blinded” (that is, they may know who is receiving the real treatment, which can bias the results). Some studies combine cupping with other treatments, so it’s not known what might have been responsible for the effect, if there was one. Most studies are also small and short term. In fact, the authors of all the reviews reporting positive results repeatedly caution about the methodological problems and call for more rigorous and longer trials.
There’s also no plausible mechanism for how cupping might provide benefits. Some practitioners believe it creates inflammation, which triggers an immune response; others use a form of cupping (massage cupping) as a type of myofascial release or trigger point therapy.
Cupping is considered generally safe, though the suctioning action bursts blood vessels under the skin, which creates the marks. Burns and blisters are also possible if a flame is used. More serious, a case report last year described subdural hematomas (bleeding between the brain and skull) that occurred in a young woman two weeks after she had cupping on her scalp to treat her headaches—though there was no definite proof that cupping was the cause.
Bottom line: The therapeutic effects of cupping remain controversial, and we remain skeptical of its benefits beyond any placebo effect. There is no scientific support for the idea that cupping helps athletes win (sorry Phelps, though you hardly needed a leg up). Still, it most likely won’t hurt to try it if you go to a well-trained practitioner—but cupping should not be done on your scalp or if you have fragile skin or a skin condition like eczema. Insurance generally won’t cover it, however, and if it doesn’t help, you’ll have the telltale marks to remind you of that—for about 10 days or so.
Also see Dealing with Painful Trigger Points.