Powered by the #1 clinical reasoning AI in the world, purpose-built for medicine, not repurposed from ChatGPT. It listens, it pushes back when needed, and it tells you the truth. When you need a prescription, a lab, or a referral, real physicians are on call.
Since you're on warfarin...
Dr. Chen prescribed sumatriptan 50mg. Sent to CVS on Main St.
Four moments where Kos puts you in control of your health.
When you need more than reasoning, like a prescription, a lab order, or a specialist referral, Kos connects you to a licensed physician who reviews your case with full context. No scheduling. No starting over.
This sounds like it needs a prescription.
Dr. Chen reviewed and approved. Prescription sent to CVS Pharmacy.
Since you're on warfarin...
Every recommendation considers your full mediacal history. Kos flags interactions, contraindications and more before you ask.
Kos analyzes your daily check-ins over weeks and surfaces patterns you'd never notice, the slow trends that matter most. This is the moment that makes people say "Kos caught what my doctor missed."
This helps me narrow down what might be going on.
Instead of "tell me more" and annoying chat follow ups, Kos collects precise clinical data through interactive forms, the same way doctors do intake. Sliders for severity. Body maps for location. Checklists for associated symptoms.
Every conversation enriches what Kos knows about you. After a month, it knows your health context better than any single doctor, because it never forgets.
Diagnosed 2019. Started metformin 500mg, increased to 1000mg in 2020. Switched to Ozempic 0.5mg in January, currently titrating to 1mg. Last A1C: 7.2, down from 8.1 in June. Responds well to dietary guidance. Prefers specific numbers over vague advice.
Prefers direct, confident language, not hedging. Wants specific medication names and dosages, not 'talk to your doctor.' Gets anxious when cancer is mentioned as a differential, so use careful framing. Likes bullet-point summaries after long discussions.
Everything else it does.
Medication Tracker
Reminders, adherence logging, and interaction checking. Always knows what you take and when.
Daily Check-In
30 seconds every morning. Your data builds into weeks of clinical insight over time.
Image Analysis
Photograph a rash, a lab report, or a prescription bottle. Kos sees it in full context.
Health Data
Syncs with Apple Health and Health Connect. Heart rate, sleep, steps, and labs flow in automatically.
Evidence Search
Cites PubMed, NEJM, and Cochrane. Real medical literature, not search engine results.
Second Opinion
On complex cases, Kos cross-checks its reasoning against a second medical AI for perspective.
A quick pulse every morning: sleep, mood, pain, energy. Over days and weeks, Kos builds a picture of your health that no doctor visit could capture. The longer you use it, the smarter it gets.
I noticed your pain trending up this week. Want to discuss?
Kos handles the entire loop. The AI reasons through your case. A licensed physician reviews and signs off. The prescription goes to your pharmacy, the lab order goes to Quest or Labcorp, the specialist is matched to your insurance. One conversation, start to finish.
Sent directly to your pharmacy. A licensed physician reviews every prescription. Kos handles the reasoning, the doctor signs off.
At 4,000+ Quest and Labcorp locations. Order directly or have a physician sign off. Your results flow back to Kos automatically.
Thousands of physicians across all 50 states. Matched to your insurance and location, with full context before you walk in.
All clinical actions reviewed by licensed physicians in all 50 states. Launching 2026.
Kos is not powered by ChatGPT. We trained our own medical reasoning model from scratch, because general-purpose AI is optimized for the wrong things. Kos is calibrated to be cautious when it should be, push back when you're wrong, and never just tell you what you want to hear. Every recommendation grounded in your profile, your history, and published evidence. On the hardest medical cases, it outperforms every model in the world.
HealthBench Hard
The hardest medical benchmark. Rare conditions, multi-drug interactions, ambiguous presentations. Where generalist AI breaks down.
Kos isn't a one-size-fits-all chatbot. It's built to handle the conditions that matter most, with the depth each one demands.
Your metformin dose, your A1C, your GLP-1 schedule. Kos tracks all of it and flags interactions before they happen.
Hot flashes at 3am don't wait for office hours. Kos tracks symptoms daily and knows which medications make them worse.
Pain is personal. Kos correlates your patterns with sleep, medications, and activity, then surfaces what changed.
Your parent is on 8 medications and their doctor visits last 12 minutes. Kos pays closer attention than anyone.
Plus anxiety, PCOS, autoimmune conditions, post-surgery recovery, and more.
Join the waitlist. Be first to experience healthcare that remembers, reasons, and acts for you.