According to the National Center for Complimentary and Integrative Health (a branch of the NIH), acupuncture is associated with multiple biological responses. These responses occur both at the point of insertion as well as at at other places in the body. Responses are related to the stimulation of sensory neurons that connect to structures within the central nervous system. This leads to activation of pathways affecting various physiological systems in the brain as well as in the periphery.
Considerable evidence shows that opioid peptides are released during acupuncture and that the analgesic effects of acupuncture are at least partially explained by their actions. Stimulation with acupuncture also activates the hypothalamus and the pituitary gland, resulting in a broad spectrum of systemic effects. Alteration in the secretion of neurotransmitters and neurohormones and changes in the regulation of blood flow, both centrally and peripherally, have been documented as well. There is also evidence that there are alterations in immune functions produced by acupuncture.
For an in-depth understanding of the biomedical basis of acupuncture, there is an excellent and thorough book on the subject called The Biology of Acupuncture. For links to specific articles and research, take a look at Related Links or visit us on Facebook.