Google's AI co-scientist and OpenAI's deep research: new partners in health research?

In February 2025, Google introduced its artificial intelligence (AI)-powered co-scientist, while OpenAI launched its Deep Research system. Both tools are designed to support researchers by processing extensive scientific literature, extracting key insights, and synthesizing relevant findings. However, critical limitations of these systems are their exclusion of paywalled research, and the inability to distinguish low-quality from high-quality research. This discussion paper highlights the implications of this constraint. Until these AI systems can integrate a more comprehensive range of scientific sources, researchers are advised to rely on well-established AI tools for literature summarization, hypothesis generation, data analysis, and research dissemination.