There are increasing concerns regarding an insidious consequence of social media: the erosion of user autonomy. The research aims to explore unreflective habit formation – an expression of loss of user autonomy - in the context of TikTok usage in Vietnam and to apply STAMP model to conceptualize the issue and the STPA method to provide actionable recommendations to the Vietnam Government. Being explorative, the research adopts desk research and qualitative methods. By integrating different concepts of autonomy in philosophy and HCI, the research identifies five key dimensions of autonomy, namely decision, execution, self-congruence, independence and system hostility. As social media exploits neurological reward cycles to reinforce user habits, user autonomy is infringed under the decision, execution and system hostility dimensions. Semi-structured interviews were conducted with 12 Vietnamese female university students in Hue during April 2025, revealing that their impulsive TikTok habitual use is unreflective. There are three main losses from this impulsive habit: time, focus capacity and identity rigidification. The responsibility for regulating social media platforms lies with the Government. They should adopt a combined strategy that integrates strict regulation of social media with comprehensive public education. These measures must be informed by up-to-date scientific research on user behavior and platform design. Regulations should not target TikTok in isolation, as the platform’s features are widely replicated across the industry. While applying STAMP model and STPA method to social media reveals both challenges and benefits, this approach is appropriate as it offers actionable insights that support targeted and comprehensive policy strategies.