The first independent safety evaluation of OpenAI's ChatGPT Health feature, published in Nature Medicine, found the tool failed to direct users to emergency care in 51.6% of cases requiring immediate hospitalization - instead recommending they stay home or book a routine appointment. The study also found ChatGPT Health frequently failed to detect suicidal ideation, with suicide crisis alerts sometimes triggering in lower-risk scenarios while failing to appear when users described specific plans for self-harm. Over 40 million people reportedly ask ChatGPT for health-related advice every day.

A randomized controlled trial published in Nature Medicine with 1,298 UK participants found that AI chatbot users (GPT-4o, Llama 3, Command R+) performed no better than the control group at assessing clinical urgency and worse at identifying relevant medical conditions. In one case, two users with identical subarachnoid hemorrhage symptoms received opposite recommendations -- one told to lie down in a dark room, the other correctly advised to seek emergency care.

The HHS-backed realfood.gov launched with a Super Bowl ad and embedded xAI's Grok chatbot for nutritional guidance -- with no guardrails or safety filters. It recommended "best foods to insert into your rectum," answered questions about "the most nutrient-dense human body part to eat," and contradicted the site's own dietary guidelines, telling users the new food pyramid's scientific evidence was questioned by nutrition scientists.

A Washington patient replaced table salt with sodium-bromide after ChatGPT said it was a healthier substitute. The patient developed bromism and psychosis, resulting in a hospital stay that doctors now cite as a warning about AI health guidance.

MD Anderson's Oncology Expert Advisor pilot burned through $62M with IBM Watson yet still couldn't integrate with Epic or produce trustworthy recommendations, so the hospital benched it after auditors flagged procurement and scope failures.

NEDA replaced its helpline with an AI chatbot (“Tessa”) that gave harmful weight-loss advice; after public reports, the organization pulled the bot.

Mental health app Koko used GPT-3 to draft replies for 4,000 users; backlash followed over consent and ethics.

Epic's proprietary sepsis predictor pinged 18% of admissions yet still missed two-thirds of real cases, forcing hospitals to comb through false alarms while the vendor scrambled to defend and retune the algorithm.

Google’s diabetic retinopathy screener rejected low-light scans and jammed nurse workflows, forcing clinics in Thailand to keep patients waiting despite the promised instant triage.

Babylon unveiled its AI symptom checker at the Royal College of Physicians and bragged it scored 81% on the MRCGP exam, but the claim could not be verified, and warned no chatbot can replace human judgment. Independent clinicians who later dissected Babylon's marketing study in The Lancet told Undark that the tiny, non-peer-reviewed test offered no proof the tool outperforms doctors and might even be worse.