Nowadays, youngsters are unceasingly active on social network sites (SNS), while being occupied with other media tasks such as watching TV. In this social media multitasking (SMM) context, adolescents are often exposed to sponsored posts by influencers. While research on adolescents’ susceptibility towards influencer marketing is starting to gain academic interest, no research until date investigated the effect of the complex multitasking context in which these messages are often consumed. This proposal therefore aims to examine the impact of SMM on the depletion of executive control and further proposes two parallel psychological processes by which adolescents’ susceptibility towards influencer marketing could be affected. The first process relates to media users’ advertising literacy and the credibility of the influencer, while the second process considers the engagement in social comparison and the consequent effects for their self-esteem. The moderating impact of type of social media behavior (active vs. passive) and repetition of the persuasive message of the influencer will be taken into account. A mix of ecological momentary assessments over 2 weeks, experimental studies and various innovative measures (e.g. eye tracking, heart rate variability, on-device data loggings, etc.) will be employed. The outcome of this project will consist of clear guidelines on how to bolster adolescents against influencer marketing when social media multitasking.