Acupuncture is a form of alternative medicine and a key component of traditional Chinese medicine (TCM) in which thin needles are inserted into the body. Acupuncture is a pseudoscience, the theories and practices of TCM are not based on scientific knowledge, and it has been characterized as quackery. There is a range of acupuncture variants which originated in different philosophies, and techniques vary depending on the country in which it is performed, but can be divided into two main foundational philosophical applications and approaches, the first being the modern standardized form called eight principal TCM and the second an older system that is based on the ancient Taoist Wuxing or better known as the five elements or phases in the West. Acupunture is most often used to attempt pain relief, though acupuncturists say that it can also be used for a wide range of other conditions. Acupuncture is generally used only in combination with other forms of treatment.

The conclusions of trials and systematic reviews of acupuncture are inconsistent, which suggests that it is not effective. An overview of Cochrane reviews found that acupuncture is not effective for a wide range of conditions. A systematic review conducted by medical scientists at the universities of Exeter and Plymouth found little evidence of acupuncture's effectiveness in treating pain. Overall, the evidence suggests that short-term treatment with acupuncture does not produce long-term benefits. Some research results suggest that acupuncture can alleviate some forms of pain, though the majority of research suggests that acupuncture's apparent effects are not caused by the treatment itself. A systematic review concluded that the analgesic effect of acupuncture seemed to lack clinical relevance and could not be clearly distinguished from bias. One meta-analysis found that acupuncture for chronic low back pain was cost-effective as an adjunct to standard care, while a separate systematic review found insufficient evidence for the cost-effectiveness of acupuncture in the treatment of chronic low back pain. .