Marketers have spent years optimizing for Google. But in healthcare, the audience has already moved on. Two thirds of physicians and three quarters of patients now turn to AI when they're researching a diagnosis, and even Google leads with an AI summary instead of ten blue links. We ran 40 health queries through Claude, ChatGPT, Gemini, Perplexity, half phrased the way a physician would ask and half the way a patient would, and sorted all 777 sources that came back. Brand content barely showed up. And as the chart below shows, the sources AI relied on changed completely depending on who was asking. Physicians got peer-reviewed literature, with academic journals cited four times as often as in patient answers. Patients got consumer health and news sites instead. The polished product pages and SEO content most brands invest in hardly entered the conversation. If this is what AI search looks like in healthcare, every industry should be asking the same question. Visibility isn't about ranking your website anymore. It's about being part of the evidence AI trusts, and that evidence looks different for every audience you're trying to reach. Zayed Yasin, our healthcare lead, breaks down what this means for life science marketers and how to start shifting budget toward the content AI actually cites: writer.com/blog/ai-engines-r…