Most Cited Sites in ChatGPT for Healthcare-Related Prompts - October 2026
Klaas FoppenMost Cited Sites in ChatGPT
for Healthcare-Related Prompts
When someone asks ChatGPT about a treatment, a medication, a health insurance question, or where to find a doctor, these are the sites it links to in its answer. Based on Promptwatch data from Sep 9 to Oct 8, 2026, collected from real healthcare prompts run through ChatGPT.
NIH leads by a wide margin, ahead of the FDA
NIH is the most cited healthcare source for organic prompts at 5.46% of all healthcare citations, across six nih.gov subdomains. Most of that comes from its research databases PubMed Central (2.38%) and PubMed (2.33%). NIH earns more than the FDA, the NHS, CMS, and SAMHSA combined.
The FDA is second at 1.76%, including its drug database on accessdata.fda.gov, and the NHS third at 1.1%. The American Society of Plastic Surgeons is the most cited non-government site at 0.64%, ahead of the American Academy of Dermatology at 0.54%. Mayo Clinic (0.49%) and Cleveland Clinic (0.4%) are the only hospitals in the chart.
Where healthcare brands should show up
- Back up medical claims with peer-reviewed studies and link to them on PubMed Central or PubMed. NIH earns more citations than any other healthcare source.
- Make sure your pages agree with official guidance from the FDA, CDC, NHS, and NICE, and link to it. Government and public health sites earn 7.06% of healthcare citations.
Citation Share by Source Type
for Healthcare-Related Prompts
Combined citation share for the 20 domains above, grouped by source type. Percentages remain a share of all healthcare citations, not just these 20 domains.
Government and public health sites earn almost half of the citations shown
The 20 healthcare sites in this chart together earn 15.54% of all healthcare citations. Government and public health sites have the largest share at 7.06%, followed by NIH and its medical research databases at 5.46%. Medical associations add 1.39%, hospitals and clinics 0.89%, reviews and directories 0.46%, and Boots, the only pharmacy in the chart, 0.28%.
Where to audit your brand's healthcare footprint
- Work with the medical associations in your specialty. The AAD and the American Society of Plastic Surgeons together earn 1.18% of healthcare citations, more than Mayo Clinic and Cleveland Clinic combined.
- Keep your Doctify and WebMD doctor profiles complete. They are the only review and directory sites in this chart, at 0.23% each.
How we collect this data
We collect millions of prompt responses, citations, and click data from the actual user interfaces of major AI platforms: over 26 billion data points and growing. This gives us one of the largest datasets on how AI search engines cite sources and recommend brands.
Real UI monitoring
Data straight from the interfaces of ChatGPT, Gemini, Perplexity, Claude, AI Overviews, and more.
26B+ data points
Over 26 billion analyzed citations, prompts, and responses, one of the largest AI search datasets available.
Continuously updated
Refreshed constantly so the trends you see reflect the latest behavior of AI search engines.
Aggregated & public
Published freely for the GEO community, based on aggregated, non-identifiable trends.
Related data reports
Most Cited Sites in ChatGPT for Software-Related Prompts - October 2026
The domains ChatGPT cited most for organic software prompts from Sep 28 to Oct 4, 2026, with a breakdown by source type.
October 6, 2026
Most Cited Sites in ChatGPT for Travel-Related Prompts - October 2026
The domains ChatGPT cited most for organic travel prompts from Sep 28 to Oct 4, 2026, with a breakdown by source type.
October 6, 2026
Track Your Healthcare AI Citation Share
See which domains AI search engines cite for your industry. Monitor your citation share against competitors and track changes in the sources ChatGPT uses.
