Introduction: Transcendental realism, the philosophical perspective dealing with the existence of causal powers governed by universal laws of nature, provides a useful framework for research conducted in the social sciences, including the field of health policy and systems research. Transcendental realism has been criticized, however, for offering weak methodological guidance for conducting research. Consequently, realist-informed studies are deemed to be less robust and less transparent, particularly regarding data analysis and synthesis towards evidence generation. In particular, the extent to which retroductive theorizing, the central evidence generating activity in realist-informed research is applied remains unclear, mysterious, and esoteric. We aimed to examine the extent to which retroductive theorizing is applied and described in realist-informed studies. Methods: We conducted a summative content analysis of 311 manuscripts included in this study. The analysis involved the counting and comparisons of the four forms of inference-making methods namely deduction, induction, abduction, and retroduction. This was followed by interpretation of the underlying context in which they were used, for example, the identification and linking of relevant constructs towards the formulation of mechanism-based theories. Findings: We found that the explicit application and description of retroductive theorizing in realist-informed studies remain minimal and inadequate. Abductive reasoning was reported in only 09/311 (2.9%) of the studies while retroduction was reported in [21/311 (6.8%)]. Abduction and retroduction, although central to realist-informed research, are seldom explicitly applied and described in such studies whereas deduction and induction, while they are meant to support retroductive theorizing, continue to dominate the process of theory formulation. Conclusion: While retroductive theorizing is less formulaic, this study highlights further methodological inadequacies within realist-informed studies. We acknowledge that it is difficult to describe inferential logic in the abstract, but recommend that realist researchers should makes their retroductive theorizing an explicit activity illustrating their critical steps in concrete applications for improved transparency and trustworthiness.