Research shows that young people’s online practices have become a continuous, seamless and routine part of their physical and social worlds. Studies report contradictory findings on whether social media promotes intoxication-driven drinking cultures among young people or diminishes their alcohol consumption. By applying actor-network theory, our starting point is that the effects of social media depend on what kinds of concerns mediate its use. Social media alone cannot make young people drink more or less but influences their drinking in relation to specific attachments that we call here ‘assemblages’. The data consist of individual interviews among girls (n = 32) and boys (n = 24) between 15 and 19 years old from Sweden, covering topics such as alcohol use, social media habits and leisure time activities. The paper maps the variety of assemblages that mediate young people’s online practices and analyzes how young people’s drinking-related social media assemblages increase, decrease or exclude their alcohol consumption. The analysis shows that social media-related attachments seem to reduce our interviewees’ use of alcohol by providing competing activities, by transforming their drinking under the public eye, by reorganizing their party rituals to be less oriented towards drinking and by facilitating parents’ monitoring of their drinking situations.