--- title: "AI Health Answer Sources: YouTube 28.4% vs the NIH's 26.7%" url: https://www.suffdigital.com/resources/data-studies/ai-health-answers-medical-sources description: "AI health answer sources: YouTube appears in 28.4% of sourced AI health answers, ahead of the NIH at 26.7%, and 67% cite a medical source. See the data." lang: en --- Share Share on X: https://twitter.com/intent/tweet?url=https%3A%2F%2Fwww.suffdigital.com%2Fresources%2Fdata-studies%2Fai-health-answers-medical-sources&text=AI%20Health%20Answers%20Cite%20YouTube%20More%20Often%20Than%20the%20NIH%3A%2028.4%25%20vs%2026.7%25 Share on Facebook: https://www.facebook.com/sharer/sharer.php?u=https%3A%2F%2Fwww.suffdigital.com%2Fresources%2Fdata-studies%2Fai-health-answers-medical-sources Share on LinkedIn: https://www.linkedin.com/sharing/share-offsite/?url=https%3A%2F%2Fwww.suffdigital.com%2Fresources%2Fdata-studies%2Fai-health-answers-medical-sources Share on Reddit: https://www.reddit.com/submit?url=https%3A%2F%2Fwww.suffdigital.com%2Fresources%2Fdata-studies%2Fai-health-answers-medical-sources&title=AI%20Health%20Answers%20Cite%20YouTube%20More%20Often%20Than%20the%20NIH%3A%2028.4%25%20vs%2026.7%25 YouTube is the most-cited website in AI answers to health questions, appearing in **28.4%** of sourced answers, ahead of the US National Institutes of Health at 26.7%. Overall, 67% of sourced AI health answers cite a government or medical source, but the rate ranges from 76.1% on ChatGPT to 33.6% on Gemini. Analysis of 4,248 AI answers to 548 health questions · answers from ChatGPT, Gemini and Google's AI features, September 2026 ## Key Findings 1. 1. YouTube appears in **28.4%** of sourced AI answers to health questions, more than the US National Institutes of Health's nih.gov at 26.7%. Copy stat 2. 2. **67%** of AI health answers that list sources cite at least one government, university, hospital, medical journal or medical association website. Copy stat 3. 3. ChatGPT cites a medical source in **76.1%** of its sourced health answers, more than twice Gemini's 33.6%. Copy stat 4. 4. Gemini gives no sources at all in **77.2%** of its health answers, against 2.7% for ChatGPT and 0.7% for Google AI Overviews. Copy stat 5. 5. AI answers to nutrition questions cite a medical source **40.8%** of the time, against 77.6% for questions about conditions, symptoms and treatments. Copy stat ## Summary Someone wakes at 3 a.m. with a stubborn headache, or a worry about a new medication, and asks an AI engine what it means. The answer comes back in seconds, with a short list of sources. Some of those sources are the National Institutes of Health and the Cleveland Clinic. Just as often, one is a YouTube video. Health questions are among the highest-stakes searches people make, and AI engines now answer many of them before anyone clicks a link. The sources behind an answer are the reader's only way to check it. For hospitals, clinics and health publishers, they also show who wins trust in AI search: institutions, consumer publishers or video creators. YouTube comes first. It appears in **28.4%** of sourced health answers, ahead of nih.gov at 26.7%, mostly because Google's AI features cite video so heavily. Two in three sourced answers, 67%, do cite at least one government or medical source, but the engine matters: ChatGPT reaches 76.1% and Gemini 33.6%. ## What we measured On September 23, 2026 we asked ChatGPT, Gemini, Google AI Mode and Google AI Overviews the same 548 health-related questions, 137 each on general health, nutrition, mental health and sleep, twice each from a US location. We collected 4,248 answers and every source they cited; 3,073 answers cited at least one source. A medical source is a government, university or military website (.gov, .edu or .mil), a major US hospital system such as Mayo Clinic, Cleveland Clinic or Johns Hopkins, a medical journal or database such as NIH and PubMed, or a medical association such as the American Heart Association, the American Cancer Society, the American Academy of Pediatrics or the World Health Organization. A sourced answer is one that lists at least one source link. Most figures are shares of sourced answers. ## YouTube is cited more often than the NIH 28.4% of sourced AI health answers cite YouTube. No single medical website appears as often. The National Institutes of Health's nih.gov appears in 26.7% of sourced answers. The Cleveland Clinic follows at 15.1%, then Wikipedia at 12.1% and the Mayo Clinic at 10.1%. Reddit (8.4%) and Facebook (6.8%) also make the top ten, ahead of WebMD, Harvard and the CDC. Sourced AI health answers citing it by website youtube.com 28.4% nih.gov 26.7% clevelandclinic.org 15.1% wikipedia.org 12.1% mayoclinic.org 10.1% healthline.com 9.8% sleepfoundation.org 9% reddit.com 8.4% facebook.com 6.8% webmd.com 6.1% harvard.edu 5.9% cdc.gov 5.6% Source: Suff Digital analysis of 4,248 AI answers to 548 health questions · answers from ChatGPT, Gemini and Google's AI features, September 2026 YouTube's lead comes from Google AI Overviews and Google AI Mode, which cite video heavily. A video can come from a hospital's own channel or from anyone with a camera, so the same link type carries both expert and amateur advice. For health organizations, it means video is a direct route into Google's AI answers on medical topics. ## Two in three sourced health answers cite a medical source Across all four engines, 67% of sourced health answers link to at least one government, university, hospital, journal or medical association website. The other third rely entirely on consumer health publishers, forums, social media and video. Counting answers that show no sources at all, the share falls to 48.3%, so fewer than half of all AI health answers point a reader to a medical institution. Most of that gap comes from Gemini, which gives no sources on most health questions. ## Medical citation rates differ widely by engine ChatGPT cites a medical source in 76.1% of its sourced health answers, the highest of the four engines. Google AI Mode (66.5%) and Google AI Overviews (65.3%) sit at about two in three. Gemini cites a medical source in 33.6% of its sourced health answers, less than half ChatGPT's rate. Sourced health answers citing a medical source by engine ChatGPT 76.1% Google AI Mode 66.5% Google AI Overviews 65.3% Gemini 33.6% Gemini also leaves most health answers unsourced. 77.2% of its health answers carry no citation at all, against 2.7% for ChatGPT and 0.7% for Google AI Overviews. The same health question can be answered from very different sources depending on the engine. ## Nutrition answers lean on non-medical websites The topic of the question matters. General health questions, about conditions, symptoms and treatments, draw a medical source 77.6% of the time. Mental health (73.2%) and sleep (70.9%) are close behind. Nutrition questions draw one 40.8% of the time, the lowest of the four. Sourced answers citing a medical source by topic General health 77.6% Mental health 73.2% Sleep 70.9% Nutrition 40.8% Nutrition is a crowded field of publishers, recipe sites and supplement brands, and AI engines draw on that wider pool. A question about vitamins or diets is far less likely to be backed by an NIH page than a question about blood pressure, which leaves more room for non-medical sources, good and bad. ## What this means for healthcare marketers If you run a practice, hospital or health content site, your competition in AI answers is not only other providers. It is the NIH, the big academic medical centers and a large amount of video. Pages that cite primary research, name a reviewing clinician and link to government guidance look like the sources AI engines already trust, and short videos from your clinicians can win the YouTube citations Google's AI features favor. Nutrition and wellness organizations have the most open field. With fewer institutional sources in those answers, a well-referenced, clinically reviewed page has a strong chance of being cited. Our healthcare seo (https://www.suffdigital.com/seo/healthcare-seo-agency) team helps health organizations structure content so AI engines can find and cite it. ## Embed this research Paste this on your site to embed the charts. It links back to the source automatically.

Source: AI Health Answers Cite YouTube More Often Than the NIH: 28.4% vs 26.7% - Suff Digital

## Cite this study APA Suff Digital. (2026). AI Health Answers Cite YouTube More Often Than the NIH: 28.4% vs 26.7%. https://www.suffdigital.com/resources/data-studies/ai-health-answers-medical-sources Plain link AI Health Answers Cite YouTube More Often Than the NIH: 28.4% vs 26.7% - Suff Digital - https://www.suffdigital.com/resources/data-studies/ai-health-answers-medical-sources ## Frequently asked questions ### What is the most-cited website in AI health answers? ### How often do AI health answers cite medical sources? ### Which AI engine cites medical sources most in health answers? ### Do AI answers about nutrition cite medical sources? ## Related studies - AI SEO 8.1% of AI Health Answers Use a Standard 'See a Doctor' Phrase: https://www.suffdigital.com/resources/data-studies/ai-health-see-a-doctor - AI SEO Gemini Answers 77.1% of Health Questions Without Citing a Source vs 2.4% for ChatGPT: https://www.suffdigital.com/resources/data-studies/ai-sources-health-questions - AI SEO AI Answers to Fitness Questions Cite nih.gov 41.5% of the Time, the Top Share of Any Industry: https://www.suffdigital.com/resources/data-studies/ai-sources-fitness-questions - AI SEO AI Cites the IRS in 76.4% of Answers to Federal Tax Questions: https://www.suffdigital.com/resources/data-studies/ai-tax-answers-irs-citations ## Structured data ```json [ { "@context": "https://schema.org", "@graph": [ { "@type": "Organization", "@id": "https://www.suffdigital.com/#organization", "name": "Suff Digital", "alternateName": "Suff Digital Marketing", "url": "https://www.suffdigital.com/", "logo": { "@type": "ImageObject", "@id": "https://www.suffdigital.com/#logo", "url": "https://www.suffdigital.com/logo.png", "contentUrl": "https://www.suffdigital.com/logo.png", "caption": "Suff Digital" }, "image": { "@id": "https://www.suffdigital.com/#logo" }, "description": "Suff Digital is a full-stack digital marketing agency that turns websites into predictable revenue engines, SEO, paid media, content, CRO, and web design built around revenue, not vanity metrics.", "slogan": "Digital marketing built for what's next.", "email": "hello@suffdigital.com", "telephone": "+1-629-236-0099", "foundingDate": "2022", "founder": { "@type": "Person", "name": "Matt Suffoletto", "jobTitle": "Founder & CEO" }, "contactPoint": [ { "@type": "ContactPoint", "telephone": "+1-629-236-0099", "email": "hello@suffdigital.com", "contactType": "sales", "areaServed": "US", "availableLanguage": [ "en" ] } ], "address": { "@type": "PostalAddress", "addressLocality": "Nashville", "addressRegion": "TN", "postalCode": "37219", "addressCountry": "US" }, "areaServed": { "@type": "Country", "name": "United States" }, "sameAs": [ "https://www.linkedin.com/company/suff-digital/", "https://www.instagram.com/suffdigital/", "https://www.youtube.com/@suffdigitalmarketing", "https://www.tiktok.com/@suffdigital" ], "knowsAbout": [ "Search Engine Optimization", "Pay-Per-Click Advertising", "Paid Social Advertising", "Conversion Rate Optimization", "Web Design", "Digital PR", "Link Building", "Website Migration", "Website Maintenance and Support", "Technical SEO", "Local SEO", "AI Search Optimization" ], "hasOfferCatalog": { "@type": "OfferCatalog", "name": "Suff Digital Services", "itemListElement": [ { "@type": "Offer", "itemOffered": { "@type": "Service", "name": "Search Engine Optimization (SEO)", "url": "https://www.suffdigital.com/" } }, { "@type": "Offer", "itemOffered": { "@type": "Service", "name": "Pay-Per-Click (PPC) Advertising", "url": "https://www.suffdigital.com/services/ppc" } }, { "@type": "Offer", "itemOffered": { "@type": "Service", "name": "Paid Social Advertising", "url": "https://www.suffdigital.com/services/paid-social" } }, { "@type": "Offer", "itemOffered": { "@type": "Service", "name": "Conversion Rate Optimization (CRO)", "url": "https://www.suffdigital.com/services/cro" } }, { "@type": "Offer", "itemOffered": { "@type": "Service", "name": "Web Design", "url": "https://www.suffdigital.com/services/web-design" } }, { "@type": "Offer", "itemOffered": { "@type": "Service", "name": "Digital PR & Link Building", "url": "https://www.suffdigital.com/services/digital-pr" } }, { "@type": "Offer", "itemOffered": { "@type": "Service", "name": "Website Migration", "url": "https://www.suffdigital.com/services/website-migration" } }, { "@type": "Offer", "itemOffered": { "@type": "Service", "name": "Website Maintenance & Support", "url": "https://www.suffdigital.com/services/website-maintenance" } } ] } }, { "@type": "WebSite", "@id": "https://www.suffdigital.com/#website", "url": "https://www.suffdigital.com/", "name": "Suff Digital", "inLanguage": "en-US", "publisher": { "@id": "https://www.suffdigital.com/#organization" } } ] }, { "@context": "https://schema.org", "@graph": [ { "@type": "Article", "@id": "https://www.suffdigital.com/resources/data-studies/ai-health-answers-medical-sources#article", "headline": "AI Health Answers Cite YouTube More Often Than the NIH: 28.4% vs 26.7%", "description": "YouTube is the most-cited website in AI answers to health questions, appearing in 28.4% of sourced answers, ahead of the US National Institutes of Health at 26.7%. 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Overall, 67% of sourced AI health answers cite a government or medical source, but the rate ranges from 76.1% on ChatGPT to 33.6% on Gemini.", "url": "https://www.suffdigital.com/resources/data-studies/ai-health-answers-medical-sources", "creator": { "@id": "https://www.suffdigital.com/#organization" }, "datePublished": "2026-09-24", "dateModified": "2026-09-24", "license": "https://creativecommons.org/licenses/by/4.0/", "isAccessibleForFree": true, "measurementTechnique": "ChatGPT, Gemini, Google AI Mode and Google AI Overviews answers" }, { "@type": "FAQPage", "@id": "https://www.suffdigital.com/resources/data-studies/ai-health-answers-medical-sources#faq", "mainEntity": [ { "@type": "Question", "name": "What is the most-cited website in AI health answers?", "acceptedAnswer": { "@type": "Answer", "text": "YouTube. It appears in 28.4% of sourced AI answers to health questions from ChatGPT, Gemini and Google's AI features, ahead of nih.gov at 26.7% (September 2026)." } }, { "@type": "Question", "name": "How often do AI health answers cite medical sources?", "acceptedAnswer": { "@type": "Answer", "text": "67% of AI health answers that list sources cite at least one government, university, hospital, medical journal or medical association website. Counting answers with no sources, the rate is 48.3%." } }, { "@type": "Question", "name": "Which AI engine cites medical sources most in health answers?", "acceptedAnswer": { "@type": "Answer", "text": "ChatGPT, with 76.1% of its sourced health answers citing a medical source. Gemini is lowest at 33.6% and gives no sources at all in 77.2% of its health answers." } }, { "@type": "Question", "name": "Do AI answers about nutrition cite medical sources?", "acceptedAnswer": { "@type": "Answer", "text": "Less often than other health topics. 40.8% of sourced AI answers to nutrition questions cite a medical source, against 77.6% for general health questions about conditions, symptoms and treatments." } } ] } ] } ] ```