The clinical efficacy of acupuncture appeared to be supported by evidence obtained from basic neuroendocrinological studies.
A number of studies have demonstrated that acupuncture may modulate a wide range of neuroendocrinological factors following stimulation of acupoints. Evidence has suggested that the clinical efficacy of acupuncture in treatment of insomnia is potentially mediated by a variety of neurotransmitters including norepinephrine, melatonin, gamma-aminobutyric acid, and β-endorphin. However, due to the complexity, these findings are far from conclusive. More research is necessary. More rigors methodology and integrated approach to evaluate both clinical and basic research evidence are required for future studies.