If there is one area that acupuncture can claim to have an effect, it's in pain relief. Although most evidence supporting acupuncture can be dismissed as anecdotal, trials have been done where acupuncture does show a pain relieving effect above placebo. The effect is not large, of the same magnitude as taking Aspirin or Ibuprofen, but nonetheless it's there and cannot be ignored.

That's not to say that there are not problems with such claims however. Pain is an entirely subjective experience; it cannot be directly measured and the severity felt depends to a large extent on the patient's state of mind which can be influenced by the practitioner giving the treatment. This leads on to the problem of blinding procedures with acupuncture. The practitioner is always aware of whether he's giving real or sham acupuncture and which patients he's giving them to. This can lead to the 'experimenter effect' influencing the outcome of trials.

The pain relief effect does seem to exist; however, it's not clear whether it's a real effect of acupuncture or a strong placebo effect that's induced in the patient by the elaborate procedure of an acupuncture treatment.