Nearly two-thirds of physicians in the United States are using an AI-powered chatbot developed by Miami-based start-up OpenEvidence to assist in diagnosing and treating patients, contributing to the company’s rapid rise to a $15 billion valuation. Founded in 2022 by entrepreneur Daniel Nadler, OpenEvidence’s platform processes medical queries by scanning peer-reviewed journals and clinical guidelines, enabling doctors to access relevant information to inform patient care decisions.
Last month, approximately 1 million U.S. physicians collectively submitted more than 42 million prompts to the service, which operates on an advertisement-supported business model. The company, which has grown largely through word of mouth, has reported bookings of $100 million in advertising commitments for 2025 and projects ad revenues between $400 million and $500 million by the close of 2026.
OpenEvidence has secured nearly $1 billion in investment over the past 18 months from major venture capital firms including Andreessen Horowitz, Blackstone, Thrive Capital, and Sequoia. Its swift market penetration stands out in contrast to more established medical software providers, with OpenEvidence launching well ahead of competitors integrating AI technologies—such as Dutch IT group Wolters Kluwer, which introduced an AI-enhanced version of its UpToDate tool in October 2025.
The service has been adopted by several prominent healthcare providers, including Mount Sinai Health System and Memorial Sloan Kettering Cancer Center in New York. Some institutions, such as NYU Langone Health, have moved to formally integrate OpenEvidence within their electronic health records, recognizing that clinicians were already independently relying on the tool. Paul Testa, NYU Langone’s chief health informatics officer, emphasized the importance of a secure, clinically informed integration to maximize utility and safety in patient care.
While many medical professionals praise the tool for streamlining information gathering and reducing workloads, questions remain regarding its accuracy and the implications of increasing dependence on AI in clinical settings. A study by the Mayo Clinic, which has invested in the company, found OpenEvidence provided accurate, evidence-based recommendations in a small sample of patient cases, though its influence on actual treatment decisions was limited. Conversely, other research, including a June paper in Nature, suggested that OpenEvidence underperformed compared to general-purpose AI models like Google’s Gemini and OpenAI’s GPT on certain clinical benchmarks.
Critics have also raised concerns about the company’s advertisement-driven business model, and OpenEvidence’s decision to exit the European Union and United Kingdom markets in response to regulatory challenges under the bloc’s AI Act has curtailed its international expansion. Despite this, investors like Mike Vernal of venture firm Conviction highlight the platform’s widespread physician adoption as a key competitive advantage.
Looking ahead, OpenEvidence plans to launch clinical trials focused on cancer and rare diseases in partnership with academic researchers. The company is also exploring broader applications of AI, including drug discovery and generating new scientific hypotheses based on existing literature. This expansion comes amid increasing competition from large AI developers such as OpenAI and Anthropic, the latter of which has recently collaborated with OpenEvidence to extend healthcare AI tools to middle-income countries.
As AI tools become more embedded in healthcare, experts caution that further research and clear clinical guidelines are necessary to ensure safe and effective integration. Concerns persist that less experienced doctors might overly rely on AI recommendations, underscoring the need for balanced adoption in clinical practice.