Villalva et al. evaluated the potential utility of anAchillea millefolium(yarrow) extract in the control ofH. pyloriinfection. The agar-well diffusions bioassay was applied to determine the antimicrobial activity of yarrow extracts. The supercritical anti-solvent fractionation process of yarrow extract was made to give two different fractions with polar phenolic compounds and monoterpenes and sesquiterpenes, respectively. Phenolic compounds were identified by HPLC-ESIMS by using the accurate masses of [M−H]−ions and the characteristic product ions. However, some of the reported product ions seem to be disputable, as described below.