There was low- quality evidence that acupuncture  improves pain compared to no treatment or st and ard treatment , but good evidence that it is no better than sham acupuncture .
The evidence for homoeopathy , spinal manipulation and herbal medicine was limited .
No firm conclusions were drawn for efficacy of either spinal manipulation or homoeopathy for FM .
Background Fibromyalgia ( FM ) is a chronic , debilitating pain disorder .
Dissatisfaction with conventional medicine can lead people with FM to turn to complementary and alternative medicine ( CAM ) .
Two previous overviews of systematic review s of CAM for FM have been published , but they did not assessed for risk of bias in the review process .
Traditional Chinese acupuncture and placebo (sham) acupuncture are differentiated by their effects on μ-opioid receptors (MORs)
Controversy remains regarding the mechanisms of acupuncture analgesia . A prevailing theory , largely unproven in humans , is that it involves the activation of endogenous opioid antinociceptive systems and mu-opioid receptors ( MORs ) . This is also a neurotransmitter system that mediates the effects of placebo-induced analgesia . This overlap in potential mechanisms may explain the lack of differentiation between traditional acupuncture and either non-traditional or sham acupuncture in multiple controlled clinical trials . We compared both short- and long-term effects of traditional Chinese acupuncture ( TA ) versus sham acupuncture ( SA ) treatment on in vivo MOR binding availability in chronic pain patients diagnosed with fibromyalgia ( FM ) . Patients were r and omized to receive either TA or SA treatment over the course of 4 weeks .  Positron emission tomography ( PET ) with (11)C-carfentanil was performed once during the first treatment session and then repeated a month later following the eighth treatment . Acupuncture therapy evoked short-term increases in MOR binding potential , in multiple pain and sensory processing regions including the cingulate ( dorsal and subgenual ) , insula , cau date , thalamus , and amygdala . Acupuncture therapy also evoked long-term increases in MOR binding potential in some of the same structures including the cingulate ( dorsal and perigenual ) , cau date , and amygdala . These short- and long-term effects were absent in the sham group where small reductions were observed , an effect more consistent with previous placebo PET studies . Long-term increases in MOR BP following TA were also associated with greater reductions in clinical pain . These findings suggest that divergent MOR processes may mediate clinical ly relevant analgesic effects for acupuncture and sham acupuncture
There was low- quality evidence that acupuncture  improves pain compared to no treatment or st and ard treatment , but good evidence that it is no better than sham acupuncture .
The evidence for homoeopathy , spinal manipulation and herbal medicine was limited .
No firm conclusions were drawn for efficacy of either spinal manipulation or homoeopathy for FM .
Background Fibromyalgia ( FM ) is a chronic , debilitating pain disorder .
Dissatisfaction with conventional medicine can lead people with FM to turn to complementary and alternative medicine ( CAM ) .
Two previous overviews of systematic review s of CAM for FM have been published , but they did not assessed for risk of bias in the review process .