“…Regarding the type of the placebo in general, plain water is one option (19,30,31,38,42,43,44), but in this case, patients could be able to identify the difference between the drug and placebo by its sweetness, hence blinding is questionable. An alternative option is the use of arti cial sweeteners (27,29,33,34,45,46,47,48, but in this case, one cannot exclude their metabolic effects (19). In our meta-analysis, the used placebos differed greatly in the studies.…”