When laypeople read controversial scientific information in order to make a personally relevant decision, information on the source is a valuable resource with which to evaluate multiple, competing claims. Due to their bounded understanding, laypeople rely on the expertise of others and need to identify whether sources are credible. The present study examined under which conditions readers acknowledge and consider available source information. University students read two conflicting scientific claims put forward by sources whose credibility was varied in terms of either expertise or benevolence. They then rated their subjective explanations for the conflicting claims, perceived source credibility, and personal claim agreement. Results showed that when evaluating and explaining the conflict, participants became vigilant to source information specifically when source credibility was questioned. Conflict explanation through differences in sources' competencies mediated the impact of sourcing on source credibility. Information about a source's benevolence revealed a strong direct effect on credibility judgments. However, motivation explanations did not clarify the relationship. Overall, findings show that readers consider source information and apply it adaptively when handling conflicting scientific information.