What is it? A traditional Chinese energy therapy. Fine needles are inserted into the skin—10 or so in a typical session—at points called meridians to free blocked qi.
Supporters say: Acupuncture's proven neurobiological effect has been widely shown to help relieve pain and nausea and improve function—for example, to ease postoperative and chemotherapy-related nausea and vomiting. In a 2004 study, acupuncture patients with osteoarthritis of the knee had less pain and an increased range of motion.
Critics say: In studies of patients who get either acupuncture or a sham version, the genuine treatment is rarely more effective. A recent study of lower-back pain showed that real and sham acupuncture worked about the same.
Risks: Very low, mostly brief side effects such as pain, fainting, or nausea. A few cases of meningitis, collapsed lung, and heart damage have been reported. Most states require disposable needles, so infections are rare.