There has been some debate in the literature as to whether GMO and GMS adsorb and reduce friction as intact glyceride esters or are hydrolysed to form the corresponding carboxylic acid that adsorbs, self-assembles, and reduces friction. Recent experiments have shown that the initial friction of GMO solutions is much lower than OA on silica surfaces. Therefore, in this study, we consider the adsorption of intact GMO and GMS molecules.