Issues in study design
Blinding of the practitioner in acupuncture remains challenging. One proposed solution to blinding patients has been the development of "sham acupuncture", i.e., needling performed superficially or at non-acupuncture sites.
A controlled study of 300 migraine patients found that both needling at non-acupuncture sites and real acupuncture resulted in improvements compared with patients on a waiting list, with no significant difference in benefit between the two groups.
A study by Ted Kaptchuk et. al. showed that sham acupuncture exerted a stronger effect on pain than an inert pill did, and concluded: "Placebo effects seem to be malleable and depend on the behaviours embedded in medical rituals."