The conclusions of many trials and numerous systematic reviews of acupuncture are largely inconsistent. An overview of Cochrane reviews found that acupuncture is not effective for a wide range of conditions, and it suggests acupuncture may be effective only for chemotherapy-induced nausea/vomiting, postoperative nausea/vomiting, and idiopathic headache. A systematic review of systematic reviews found little evidence of acupuncture's effectiveness in treating pain. The evidence suggests that short-term treatment with acupuncture does not produce long-term benefits. Some research results suggest acupuncture can alleviate pain, though the majority of research suggests that acupuncture's effects are mainly due to placebo. A systematic review concluded that the analgesic effect of acupuncture seemed to lack clinical relevance and could not be clearly distinguished from bias.
Acupuncture is generally safe when done by an appropriately trained practitioner using clean needle technique and single-use needles. When properly delivered, it has a low rate of mostly minor adverse effects. Accidents and infections are associated with infractions of sterile technique or neglect of the practitioner. A review stated that the reports of infection transmission increased significantly in the prior decade. The most frequently reported adverse events were pneumothorax and infections. Since serious adverse events continue to be reported, it is recommended that acupuncturists be trained sufficiently to reduce the risk. A meta-analysis found that acupuncture for chronic low back pain was cost-effective as an adjunct to standard care, while a systematic review found insufficient evidence for the cost-effectiveness of acupuncture in the treatment of chronic low back pain.
Scientific investigation has not found any histological or physiological evidence for traditional Chinese concepts such as qi, meridians, and acupuncture points, and many modern practitioners no longer support the existence of life force energy (qi) flowing through meridians, which was a major part of early belief systems. Acupuncture is believed to have originated around 100 BC in