Social Networking Service/Site (SNS) use is deemed a double-edged sword: despite being a source of unlimited communication, networking possibilities, and entertainment, SNS can foster addiction symptoms and worsen mental health. The unprecedented growth of SNS use globally raised discussions about the need to manage SNS use and the possible tools and methods to do so. This study attempted to conduct and test an intervention which incorporated a cognitive-behavioral technique of self-reflection journaling to help participants manage and reduce their SNS use. A total of 68 participants aged 18–25 years monitored their daily SNS use by submitting their screen time from their smartphones during a period of seven days, and again, during another five days of follow-up after a 14-day break. During the seven-day period, participants (n₁ = 34) in the experimental group applied a cognitive-behavioral technique of self-reflection and submitted daily journal entries, while participants in the control group (n₂ = 34) only monitored and submitted their screen time. The findings suggest that the daily self-reflection and journaling did not significantly reduce SNS use of participants in the experimental group, as the SNS use of both groups did not significantly decrease over the 7-day period. Additionally, no significant differences were observed in the SNS use duration between the two groups during the follow-up stage. The study findings suggested that screen time monitoring and self-reflection did not lead to significant behavioral changes in this short intervention period, and more research is needed to shed light on effective tools for intervention.