In two studies we explore how different levels of social networking sites (SNSs) use affect the psychological constructs of well-being, social connection, and social capital. Conducting two studies and using a multiday experimental design in both an individualistic (United Kingdom [U.K.]) and a collectivistic (Bulgaria [BG]) society, we investigated differences in the effects of abstaining from SNS use, overuse, and normal use. Participants (U.K. n = 116; BG. n = 120) in the two within-subject studies reported on connectedness and two types of social capital (bridging; bonding), and their well-being, on days in which they had lower use of social media, used it as normal, or overused it. Results revealed no significant differences on well-being scores across the three conditions for the U.K. and Bulgaria. Social connection and bonding social capital significantly decreased on lower use days in the U.K. sample. These effects were not replicated in the Bulgarian sample. Findings did not indicate significant differences on the scores for bridging social capital across the three levels of SNS use for the participants from the U.K. and from Bulgaria. For the U.K. sample, social connection, in particular, served as an independent mediator linking lower use days to lower well-being, in contrast with normal use days. Suddenly lowering one’s social media use might lead to people experiencing less connected to others, thus impacting their well-being. However, overuse of SNS platforms is still underexplored, thus people should regulate their SNS use in an optimal way which best supports their daily lives.