The purpose of this study was to evaluate the effect of three swallowing aids on the adsorbent properties and palatability of a mixture of the oral charcoal adsorbent, Kremezin®. None of the swallowing aids had any effect on the adsorption of indole by Kremezin®, either in vitro and in vivo. In gustatory sensation tests of the palatability of the swallowing aids with Kremezin®, 14 items were evaluated according to the semantic differential (SD) method. Factor analysis of the results identified two main factors 'Remaining after removing from mouth' and 'Sense of holding in mouth' as predominantly determining the palatability. The swallowing aid with the highest viscosity allowed the best dispersion of Kremezin®, and also improved the palatability of Kremezin® the most.