Scientists occupy conflicting roles as stakeholders in the policy-making process. While scientific credibility is traditionally grounded in the CUDOS norms—communalism, universalism, disinterestedness, and organised skepticism—policy impact frequently requires scientists to step beyond these ideals and engage with political, commercial, or advocacy interests. Through case studies such as the public debate over gas stove safety we explore how scientists are drawn into stakeholder positions, often motivated by a desire to inform or influence policy. To structure the analysis, Roger Pielke’s framework of scientist roles is introduced—comprised of the Pure Scientist, Applied Scientist, Issue Advocate, Science Arbiter, Honest Broker, and Science Advisor (to which is added the Policy Wonk). We interpret how each role navigates between preserving epistemic integrity and meeting regulatory or political expectations. Scientists face a Catch-22: the more they adhere to objective communication, the less persuasive they are to policymakers and the public. In contrast, advocacy compromises the CUDOS norms that underpin their authority. Science input is distorted in high-stakes, value-laden debates where urgency demands action before consensus is reached. Boundary organisations such as Europe’s Scientific Advice Mechanism (SAM) attempt to structure and insulate science input from overt political influence, while still rendering it “policy-ready.” Ultimately, scientists cannot remain apolitical observers in contentious policy arenas—they must choose how to engage, knowing that both action and inaction have consequences for public trust and policy outcomes.