Background: Artificial intelligence has been reshaping many industries, and education is no exception. When ChatGPT burst onto the scene in late 2022, it ignited conversations among educators and researchers alike. Despite growing interest and experimentation with this technology in university classrooms, the field has been missing a comprehensive analysis of the actual research examining how ChatGPT is being used in higher education settings. Objectives: This review addresses that gap by focusing on experimental designs and interventions that incorporate ChatGPT in higher education settings, with particular attention to its impact on academic outcomes. Methods: This study followed the PRISMA guidelines to identify and analyse relevant experimental studies. Through systematic coding and analysis of 21 selected studies, this review examined research design, intervention types and academic outcomes. Results and Conclusions: This review found that research on ChatGPT-based interventions in higher education has focused on language and STEM domains. Although many of the studies are true experimental designs, they often lack large, diverse samples. Two main types of interventions are identified: task assistance and general learning support, each with unique strengths and challenges. ChatGPT was generally effective for knowledge acquisition, but its impact on skills development varied. Medium-term interventions showed the best results, while short-term effects were limited and long-term outcomes were mixed.