This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider for medical decisions.

TL;DR: Buoy Health is an AI symptom checker founded at Harvard in 2014 and backed by Cigna Ventures, Humana, and Optum Ventures. It raised approximately $87 million but has not secured new funding since November 2020. Slothwise is an AI health assistant that connects to your medical records, wearables, and lab results for continuous health monitoring. Slothwise is independently built and listed on Medicare.gov, one of only 13 apps selected out of 350,000+. Buoy is not.

What are Buoy Health and Slothwise?

Buoy Health is an AI-powered symptom checker founded in 2014 at Harvard Innovation Labs by Andrew Le, MD. You describe your symptoms to Buoy's AI chatbot, it asks follow-up questions based on a clinical algorithm trained on over 18,000 medical studies, and then suggests possible conditions and appropriate next steps. Buoy also operates a healthcare marketplace that connects users to partner services for care options. It has raised approximately $87 million in venture funding, with its last round (a $37.5 million Series C in November 2020) led by Cigna Ventures and Humana, with participation from Optum Ventures.

Slothwise is an AI health assistant that connects to your medical records from over 60,000 hospitals and clinics, syncs with 300+ wearable devices, and learns what is normal for you. It surfaces insights when something needs attention, explains lab results, checks medications against FDA safety alerts, tracks daily habits, and prepares doctor visit summaries. It is independently built with no external funding and is listed on the CMS Medicare App Library on Medicare.gov.

Think of Buoy as a starting point: "I have a symptom, what should I do?" Think of Slothwise as an ongoing companion: "Here is your full health picture, here is what is changing, and here is what to bring up with your doctor."

How do their features compare?

• AI symptom assessment: Both use AI to help you understand health concerns. Buoy focuses on symptom triage: you describe what you feel, and it suggests possible conditions and care paths. Slothwise's AI answers health questions grounded in your actual medical records, lab results, and wearable data.

• Health records: Buoy does not connect to your medical records from hospitals or clinics. Slothwise connects to over 60,000 hospitals and clinics via Fasten Health.

• Wearable and device tracking: Buoy does not integrate with wearables. Slothwise syncs with 300+ devices including Apple Health, Garmin, Oura, Whoop, and Fitbit.

• Lab result interpretation: Buoy does not interpret lab results. Slothwise interprets 200+ lab markers with age- and sex-stratified reference ranges and tracks trends.

• Care navigation: Buoy connects users to a marketplace of healthcare services and partner companies. It was designed to route you toward care options, including services from partners like Hinge Health and LetsGetChecked. Slothwise prepares you for care by generating doctor visit summaries and providing personalized preventive health checklists.

• Ongoing monitoring: Buoy is a single-session tool. Once you get your symptom assessment, the interaction ends. Slothwise monitors your health data continuously and surfaces insights over time.

• Daily health tracking: Buoy does not offer tracking. Slothwise tracks food, medications, hydration, weight, mood, blood pressure, blood glucose, and menstrual cycles.

• Medical bill analysis: Buoy does not analyze medical bills. Slothwise explains charges and identifies potential billing errors.

• Pricing: Buoy's symptom checker is free. Slothwise has a free tier (50 messages, no credit card required) and a Pro subscription at $7.99/month.

• Text messaging access: Buoy requires a web browser or app. Slothwise is accessible via text message with no app download required.

What does Buoy Health do better?

Buoy was one of the first AI symptom checkers, and its clinical pedigree is real. The algorithm was developed at Harvard and the company was founded by a physician. It earned backing from three of the largest healthcare companies in the United States.

• Clinical foundation: Buoy's AI was built on an algorithm trained on over 18,000 medical studies, developed at Harvard Innovation Labs.

• Healthcare marketplace: Buoy connects users to partner care services, making it easier to act on a symptom assessment by routing you to relevant providers and services.

• Enterprise integration: Employers and health plans can integrate Buoy into their benefits platforms, surfacing benefits information and routing employees to in-network providers. If your employer uses Buoy, it may already be available to you at no cost.

• Free: The symptom checker costs nothing to use.

What does Slothwise do better?

Buoy was designed to answer one question: "What could this symptom be, and where should I go?" Slothwise was designed to answer a broader one: "What is happening with my health, and what should I be paying attention to?"

The difference is depth and continuity. Buoy does not know your medical history, your lab results, your medications, or what your heart rate has been doing over the past month. Slothwise connects to all of that and uses it to surface patterns and insights you would not catch on your own.

There is also a question of who the product was built for. Buoy's largest investors are Cigna Ventures, Humana, and Optum Ventures, three of the largest health insurance and healthcare services companies in the United States. The enterprise product routes users toward partner services and benefits platforms. Slothwise has no external investors. No corporate backers. Every product decision is made for the patient.

Buoy has not raised funding since November 2020. Slothwise is listed on the CMS Medicare App Library on Medicare.gov in April 2026, one of only 13 apps selected out of more than 350,000 health apps worldwide, alongside Microsoft, Samsung, Noom, and Zocdoc. It has earned the DiMe Seal for quality and trust in digital health. Buoy holds neither credential.

Who should choose which?

• Choose Buoy Health if you have a specific symptom right now and want a quick, free assessment of what it might be and where to go for care, especially if your employer or health plan already provides Buoy as a benefit.

• Choose Slothwise if you want an AI health companion that connects to your medical records, monitors your health over time, explains your lab results, tracks your daily habits, and is independently verified on Medicare.gov.

• Use both: Buoy and Slothwise serve different moments. Use Buoy for a quick symptom check when something new comes up. Use Slothwise for the bigger picture: understanding your records, tracking trends, preparing for doctor visits, and getting ongoing health insights grounded in your actual data.

This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider for medical decisions.