See It In Action
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Trustworthy health information, powered by AI.
In today's information-saturated world, finding accurate health information is overwhelming. With 7% of Google's daily searches being health-related (70,000 requests per minute), users struggle to distinguish trustworthy sources from misinformation. Truth Serum solves this problem by leveraging Retrieval Augmented Generation (RAG) and advanced AI to deliver accurate, evidence-based answers drawn only from MedlinePlus, the U.S. National Library of Medicine's trusted health information service, with a link to every page it used.
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Traditional search engines overwhelm users with links, sponsored content, and often conflicting information. Research shows that 28.8% of health information on social media is misinformation. Truth Serum answers directly, and only from MedlinePlus.
Answers come only from MedlinePlus, the National Library of Medicine's health information service: 2,020 pages, no ads, no sponsored content. When those pages don't answer a question, Truth Serum says so instead of guessing.
Retrieval Augmented Generation: semantic search finds the five most relevant of 105,088 passages, and a language model writes a concise answer from them. No sorting through dozens of result pages.
Each answer lists the MedlinePlus pages it was written from, so you can read the original yourself. The model is told to use those passages and nothing else, and any link it names that wasn't in them is dropped.
Five free searches, then a free Google account for ten a day. Cloudflare Turnstile keeps bots out, and a daily cap keeps the whole service inside Cloudflare's free tier, so it costs nothing to run.
Unlike general-purpose search engines, the crawler indexes one trusted health site, following its sitemap and robots.txt, so data quality is set from the ground up.
Get information in a user-friendly, readable format with clear source attribution. Compare information across multiple pages from the same domain to see the full picture.
1. Focused crawling: MedlinePlus is crawled through its sitemap.xml, respecting robots.txt and rate limits.
2. Sanitization & chunking: pages are cleaned to plain text and split into passages: 105,088 from 2,020 pages.
3. Vector storage: every passage and its 1536-dimension OpenAI embedding lives in SQLite Durable Objects on Cloudflare, split across four shards.
4. Retrieval: a compact int8 index of each vector's first 256 dimensions finds candidates in a few milliseconds, then exact cosine similarity on the full vectors picks the top five.
5. Answer generation: Workers AI (Gemma 4 26B) writes the answer from those five passages only, as a markdown summary with key points and source links.
6. Fair free use: five searches per visitor, then Google sign-in for ten a day, with Turnstile against bots and a daily cap that stays within Cloudflare's free tier.
2,020 pages and 105,088 passages, crawled in mid-2026. Every answer links back to the pages it used.
The Problem:
The Solution: Truth Serum eliminates the noise by providing direct, accurate answers from sources you can trust.
How it's built — pick a version, open it and step through