Current scientific research supports acupuncture's efficacy in the relief of certain types of pain and post-operative nausea. Other reviews have concluded that positive results reported for acupuncture are too small to be of clinical relevance and may be the result of inadequate experimental blinding, or can be explained by placebo effects and publication bias.
The invasiveness of acupuncture makes it difficult to design an experiment that adequately controls for placebo effects. A number of tests comparing traditional acupuncture to sham procedures found that both sham and traditional acupuncture were superior to usual care but were themselves equivalent, findings apparently at odds with traditional theories regarding acupuncture point specificity.
Acupuncture's use for certain conditions has been endorsed by the United States National Institutes of Health, the National Health Service of the United Kingdom, the World Health Organization, and the National Center for Complementary and Alternative Medicine, Some scientists have criticized these endorsements as being unduly credulous and not including objections to or criticisms of the research used to support acupuncture's effectiveness.
