I Built a Custom GPT to Manage My Supplements

What's Actually Going On Inside You (AI Can Now Tell You)

Hamish Grierson, co-founder and CEO of Thriva, gives a screen-share tour of how the UK blood-testing company turns your results into action. We go through Compass (three tests a year, chosen for you based on your goals and history), how Thriva benchmarks your markers against people your own age and sex rather than a sick population, and the difference between being "in range" and actually being optimal. Then Hamish shows the Healthspan dashboard — blood data sitting alongside Oura, Garmin and Whoop in one view — and demos the new Thriva Health Assistant live, fielding a cholesterol question and an Omega-3 dinner query with full longitudinal context. This is what happens when a purpose-built AI has your actual blood history, not just the test you paste in. Timestamps 00:00 Cold open 00:32 Why Hamish co-founded Thriva 02:10 The problem with standard blood test ranges 04:05 Thriva Compass: choosing your three tests a year 07:20 Live demo: reading a Thriva results dashboard 09:45 Optimal vs in-range 12:00 Healthspan dashboard: blood + wearables in one view 15:30 Why wearables without blood context miss half the picture 17:45 Introducing the Thriva Health Assistant 19:10 Demo: cholesterol question with full blood history 22:00 Demo: Omega-3 dinner query 24:15 What the Health Assistant cannot do 25:30 Wrap-up

The Best Vibe-Coded Health System We've Ever Seen

Mike Hudack (CEO of Sling Money, former executive at Meta, Monzo and Deliveroo) built a personal health data platform almost entirely using Claude Code — connecting his whole genome sequencing, blood tests, Oura Ring, 13 years of Withings data, and workout logs into one AI system. He did it as a side project, with prompts, while running a startup and raising three kids. In this episode, Mike walks through the exact system and how it caught something none of his individual apps could: a specific overtraining period, identified by cross-referencing HRV data with blood tests and workout logs. He also demos a food tracker he built in 10 minutes and explains why he's returning his Whoop. LINKS & RESOURCES - Claude Code: https://claude.ai [https://claude.ai] - Oura Ring: https://ouraring.com [https://ouraring.com] - Withings: https://www.withings.com [https://www.withings.com] - Strong App: https://www.strong.app [https://www.strong.app] - DNAComplete.com [http://DNAComplete.com]: https://www.dnacomplete.com [https://www.dnacomplete.com] - SNPedia: https://www.snpedia.com [https://www.snpedia.com] - ElevenLabs: https://elevenlabs.io [https://elevenlabs.io] - OpenAI API: https://openai.com [https://openai.com] TIMESTAMPS 0:00 Introduction 1:30 Mike's background — Facebook, Deliveroo, Monzo, Sling Money 3:02 Building a food tracker in 10 minutes 3:59 AI detects overtraining from cross-referenced data 5:30 Whole genome sequencing analysis with Claude Code 8:23 Why conversational AI beats dashboards 9:46 Claude vs ChatGPT as your doctor 11:00 Layering data: Oura, Withings (13+ years), Strong app 13:30 The FatSecret problem — £1,500/month for UK access 15:00 MCP server architecture 16:50 Why Mike is returning his Whoop 18:00 WhatsApp-based health AI via Open Claude 19:24 "Most exciting thing in the last hundred years" 20:30 Proactive daily health summaries ━━━━━━━━━━━━━━━━━━━━━━ ABOUT HEALTHSTACKS AI workflows for training, nutrition, and recovery you can steal today. Hosts: Will Read & James Grant Website: https://healthstacks.ai [https://healthstacks.ai] Subscribe for new episodes every Wednesday ━━━━━━━━━━━━━━━━━━━━━━ #HealthStacks #AIHealth #ClaudeCode #OuraRing #Whoop #GenomicData #HealthData #PersonalAI

How I Built an AI That Personalises Workouts to My Body: HealthStacks with James McAulay

James McAulay connected his Garmin, Strava, TrainingPeaks, gym app, and a 65-page blood work report into a single AI coaching system inside Claude Desktop — no code required. He runs four live demos showing exactly how it works. The system critiques recent runs using sleep and HRV data, designs structured workouts based on readiness metrics, spots gaps in gym programming, and personalises post-workout nutrition from specific blood markers. What you'll learn: - How to connect multiple health data sources to one AI agent using MCP servers - A system prompt structure that gives AI enough context to actually coach you - How to turn blood work into personalised, actionable nutrition guidance - The honest limitations — what AI coaching can and cannot replace Resources: www.healthstacks.ai/episodes/ep3-james-mcaulay

I Built a Custom GPT to Manage My Supplements

James walks through how he built a custom GPT that knows his blood work, health goals, and red lines — and how it recently told him to stop taking glycine. In this episode, you'll see: - How to build a custom GPT that acts as your personal supplement advisor - A prompting technique that compensates for gaps in your own knowledge - Why stacking similar supplements can work against you (and how AI catches it) - How to design 8-12 week experimental review protocols with pass/fail criteria - When to default to your doctor and when AI is the better prep tool Timestamps 00:00 Introduction 00:30 HealthStacks show intro 01:06 Origin story — the scatter-gun approach before AI 02:10 Why experimentation loops matter 03:21 Key principle: start with goals, not supplements 04:02 Screen share: building the Custom GPT 06:19 Three health goals explained 08:25 System instructions deep-dive 08:57 Prompting technique: "ask me clarifying questions" 10:14 Getting started advice for beginners 14:17 Case study: why James removed glycine 17:10 "Top 5 interventions" live demo 18:17 Role prompting: specialist vs. generalist 21:34 Results walkthrough 24:08 Building a full daily stack with dosing schedule 27:04 The future of the supplement industry 29:13 Failures: when the same AI gives conflicting advice 30:34 Final stack review 32:50 Wrap-up and takeaways Resources ChatGPT Custom GPTs: https://chatgpt.com [https://chatgpt.com] Randox Health: https://www.randox.com [https://www.randox.com] GlyNAC: https://examine.com/supplements/glycine/ [https://examine.com/supplements/glycine/] Ashwagandha: https://examine.com/supplements/ashwagandha/ [https://examine.com/supplements/ashwagandha/] Yeast Beta-Glucan: https://examine.com/supplements/beta-glucan/ [https://examine.com/supplements/beta-glucan/] Urolithin A: https://examine.com/supplements/urolithin-a/ [https://examine.com/supplements/urolithin-a/] Website: https://healthstacks.ai [https://healthstacks.ai] #supplements #ai #health #customgpt #biohacking #healthstacks

How I Fact-Check Health Claims Before Buying Anything: HealthStacks Episode 1

Stop wasting money on supplements that don't work for you. In this episode, I show you the exact 3-step workflow I use to fact-check health claims, personalize recommendations to my blood work, and find high-quality products at the best price. Will Read demonstrates how he uses Consensus.app [http://Consensus.app] to search peer-reviewed research, then ChatGPT with his blood test data to check if supplements are actually right for him — including how AI caught a potential problem with his multivitamin. 🔗 RESOURCES FROM THIS EPISODE • Consensus.app [http://Consensus.app]: https://consensus.app [https://consensus.app] • Examine.com [http://Examine.com]: https://examine.com [https://examine.com] • Full show notes: https://healthstacks.ai/episodes/001-bogus-health-claims [https://healthstacks.ai/episodes/001-bogus-health-claims] ⏱️ TIMESTAMPS 0:00 Introduction 1:03 The problem: 15 years of conflicting health advice 2:44 Demo: Testing BCAAs in Consensus.app [http://Consensus.app] 5:17 Red flags that make me reject a supplement 6:42 Positive example: Researching creatine 8:49 When science disproves what you've heard 10:03 Beyond supplements: Training and sauna research 12:40 Personalizing with ChatGPT and blood tests 14:46 Why iron supplements weren't right for me 16:17 AI catching a multivitamin conflict 19:11 Shopping for quality supplements 22:28 Is all this research worth the time? 23:51 The complete workflow 🎙️ ABOUT HEALTHSTACKS AI workflows for training, nutrition, and recovery you can steal today. New episodes weekly-ish. 🔔 Subscribe: https://youtube.com/@HealthStacksAI [https://youtube.com/@HealthStacksAI] 🌐 Website: https://healthstacks.ai [https://healthstacks.ai]