PEG-120 methyl glucose dioleate is a polyethylene glycol ether of the diester of methyl glucose and oleic acid. The number associated with the ingredient name (i.e., PEG-120) corresponds to the number of repeat units of ethylene glycol. The PEG portion of this ingredient is hydrophilic (attracted to water) and the methyl glucose dioleate portion is lipophilic (attracted to oil). This structure enables PEG-120 methyl glucose dioleate to function as a surfactant and emulsifier in cosmetics and personal care products.

Surfactants attract and suspend oil, dirt, and other impurities on the skin and allow them to be washed away. PEG-120 methyl glucose dioleate is most often used as a surfactant in shower gels, facial cleansers, and shampoos. As an emulsifier, PEG-120 methyl glucose dioleate can be used in formulations that contain both water and oil components. Mixing water and oil together creates a dispersion of oil droplets in water (and vice versa). These two phases can separate if the product is left to settle. To address this problem, an emulsifier can be added to help the droplets remain dispersed.