Our findings raise questions on routinely accepted informed consent procedures: ethical standard requires every detailed information including placebo should be given to study participants. Placebo information in other than acupuncture trials, however, has been reported far from fully informing  and what information is provided to the patient about side effects is known to modulate treatment responses often to enhance nocebo effect [8, 48]. Moreover, as we have few empirical findings on how patients are told about placebo may affect blinding and study outcomes, future studies are needed to examine this unanswered question.