Comparison

Carbon vs Function Health

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Carbon

This app provides personalized nutrition plans for weight loss, muscle gain, or maintenance. It adapts your plan as you progress and offers a comprehensive food tracker with a large database and barcode scanner. It supports various diet preferences and allows for custom meal planning.

Highlights
  • Personalized nutrition plans
  • Adaptive plan adjustments
  • Comprehensive food logging
  • Barcode scanner
  • Diet preference customization
  • Diet planner for flexible eating
Features
Read full description

Carbon Diet Coach is your nutrition solution for results that LAST. Whether your goal is to lose fat, build muscle, improve your metabolism, or simply maintain your weight, Carbon Diet Coach removes the guesswork. Carbon Diet Coach is a science-based nutrition app designed by renowned nutrition coaches Dr. Layne Norton (Ph.D. Nutritional Sciences) and Registered Dietitian Keith Kraker (BS Dietetics). It does everything a normal nutrition coach would but at a fraction of the cost. Simply select your goal, answer a few short questions, and it does the rest! You will get a customized nutrition plan based on YOUR goals and metabolism. What's more, Carbon will adjust the plan as you progress to optimize your results. If you hit a plateau or stall, Carbon will make adjustments to keep you progressing towards your goal, just like any good coach would. Our coaching system uses the latest techniques in nutrition science to make sure you get the best results possible. All you need to do is follow these simple steps: ∙ Log your food using the built-in food tracker ∙ Log your body weight ∙ Check-in each week Do that and Carbon does the rest! Carbon Diet Coach can do things other nutrition coaching apps can’t do. For example, your nutrition plan can be tailored to your diet preference: ∙ Balanced ∙ Low Carb ∙ Low Fat ∙ Ketogenic ∙ Plant-Based Each setting is completely customizable so that you receive a plan that is sustainable for YOU! Another feature that makes Carbon unique is the diet planner. Want high and low-calorie days rather than eating the same foods every day? Use the diet planner to set up your week and stay on track. Overate on one day and not sure what to do with your nutrition plan for the rest of the week? Adjust the diet planner to account for what you overate and Carbon does the rest! Other coaching features include: ∙ Adjustable check-in days ∙ Check-in explanations so you're never left wondering why the app did or didn’t make a change ∙ Check-in history so you can look back and see why the app made various adjustments ∙ Charts showing your weight, body fat, lean body mass, calorie intake, protein intake, carbohydrate intake, fat intake, and metabolic rate ∙ Early check-in feature for those who can’t always check in on their specified day ∙ Goal tracker so you can see the progress you’ve made and how close you are to your goal ∙ Recommendations after you reach a goal so you can plan for what's next and KEEP your results ∙ Integrates with Apple Health to automatically read Body Weight and Body Fat values Already know what you are doing with nutrition and don’t need Carbon to coach you? No problem, you can enter your nutrition targets and simply use the food tracker. Beyond the amazing coaching features of this app is a food tracker that's excellent in its own right. Its features include: ∙ A huge food database ∙ Barcode scanner ∙ Quick add macros ∙ Copy meals ∙ Favorite foods ∙ Create custom foods ∙ Create custom recipes No matter what your goal is, Carbon Diet Coach is your solution. Simple. Scientific. Sustainable. App Subscriptions: ∙ Monthly ∙ 6 Months ∙ Yearly The subscription period will automatically renew unless auto-renew is turned off at least 24 hours before the end of the current subscription period. To turn this function off, simply go to your iTunes account and turn off auto-renew. Renewal payments will differ depending on subscription and pricing at the time of renewal. Your iTunes account will be charged when the purchase is confirmed. Food database powered by FatSecret: https://fatsecret.com Terms and Conditions: https://joincarbon.com/terms-and-conditions/ Privacy Policy: https://joincarbon.com/privacy-policy/

About

Function Health

Gain deep insights into your health with advanced lab testing, personalized protocols, and AI-powered chat. Understand your body's evolution and make informed changes with data-backed guidance. Includes options for advanced imaging and convenient blood draws.

Highlights
  • 160+ lab tests annually
  • Personalized health protocols
  • Private AI Chat for results
  • Advanced MRI & CT scan options
  • Home or office blood draws
  • Connect wearables
  • Upload health records
Features
Read full description

Function membership helps you take control of your health with 160+ lab tests each year, personalized Protocols, and Private AI Chat powered by Medical Intelligence—all backed by advanced science and your real data. Built with top doctors, Function gives you the power to understand your body, track how it evolves, and make meaningful change. NOW AVAILABLE: HOME OR OFFICE BLOOD DRAWS Schedule a concierge blood draw at your home or office. A licensed specialist comes to you and completes your blood draw in under 20 minutes. Available in select locations. 160+ LAB TESTS Membership includes testing for your heart, hormones, thyroid, liver, kidneys, toxins, nutrients, inflammation, autoimmunity, immunity and more. ADVANCED MRI & CT SCANS Detect early signs of cancer and hundreds of other potential conditions with the option to purchase advanced imaging for your brain, pancreas, liver, spine, ovaries, prostate, heart and much more. MEDICAL INTELLIGENCE Built with leading medical scientists, Function’s proprietary model brings together your health history and insights from a large population to help you better understand your health and find steps you can take today to support your health over time. PRIVATE AI CHAT Ask questions about your results, identify meaningful patterns, and figure out where to focus next, with Private AI Chat—powered by Medical Intelligence and built in partnership with top clinicians. CONNECT WEARABLES Connect Apple Health and other health devices and wearables to see how your activity, sleep, and daily habits affect your lab test results and long-term health. PROTOCOLS Translate your lab results, scans and health history into clear, evidence-based plans for nutrition, activity, and supplements—all customizable to your goals and preferences. UPLOAD HEALTH RECORDS Upload past lab test results, scans, and other medical records for a more complete view of your health, all in one secure place. PROGRESS YOU CAN SEE Twice-yearly and On-Demand testing helps you track your results over time, monitor for early signs of disease, and identify where to focus next. ADVANCED LAB TESTS Membership includes 160+ lab tests, plus the option to purchase advanced On-Demand tests for: - Detection of 50+ cancers - Alzheimer’s risk detection - MTHFR gene variants - Advanced MRI and CT scans starting at $365 - Food allergies and sensitivities - …and much more ACCESSIBILITY What could cost as much as $15,000 on your own is included with membership for just $365/year. Lab testing is available at over 2,000 lab locations across the US, with no insurance needed. SECURITY Function was built for privacy and security. Function is built to HIPAA standards. Your information is secure. How it works: 1. Join Function and schedule your first set of lab tests. 2. Get your results and personalized Protocols. Ask questions with your Private AI Chat. 3. See your progress with 60+ lab tests at your Mid-Year Test. 4. Purchase MRI or CT scans and other advanced On-Demand Tests any time. DISCLAIMER Function Health is a technology company and not a laboratory or medical provider. All laboratory and medical services are provided by independent third parties. Function Health does not offer medical advice, laboratory services, a diagnosis, medical treatment, or any form of a medical opinion; its services are not a substitute for medical care, medical advice, and/or a detailed discussion with a physician or other licensed provider. If you have any questions regarding any laboratory results or any other information that you access through Function Health, you should contact a physician or other licensed provider. All material, information, data, and content that Function Health provides is strictly for general information purposes. For additional important information: https:// www.functionhealth.com/terms-of-service.

Screenshots

Carbon4 screens
Function Health4 screens

Verdict

The call

The clearest difference is in-app purchases: Function Health at none against Carbon's 9. Function Health also leads on ratings volume (25K vs 8.1K). Carbon's advantage is review sentiment (79% vs 62%) and chart position (#100 vs unranked). On price, rating, update cadence and ads there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Carbon sells 9 in-app purchases, starting at $11.99 per month. Function Health asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.8 for Carbon against 4.9 for Function Health. Both are backed by a comparable volume of ratings — 8.1K and 25K respectively. Written reviews are what separate them: 79% of Carbon's written reviews are positive against 62% of Function Health's.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly weekly. Both last shipped on October 31, 2026.

Scorecard5 real differences · 6 level
Carbon versus Function Health: the parameters behind the verdict, then further details
ParameterCarbonFunction Health
PriceFreeFree
Rating4.8 (8.1K ratings)4.9 (25K ratings) — better
Positive reviews79.4% of reviews — better61.5% of reviews
Number of ratings8.1K25K — better
Update frequencyWeeklyWeekly
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
Best chart rank#100 — better—
DevicesiPhoneiPhone
Requires iOS16.616.4 — better
Further details — not scored
Size106 MB205 MB
Age rating17+17+
DeveloperReform LLCFunction Health

Customer experience

Carbon

All ratings8,002 ratings
Positive95.9%
Neutral1.4%
Negative2.6%
Written reviews452 reviews
Positive79.4%
Neutral6.4%
Negative14.2%

Function Health

All ratings25,084 ratings
Positive99.0%
Neutral0.4%
Negative0.6%
Written reviews351 reviews
Positive61.5%
Neutral5.7%
Negative32.8%

User reviews

Carbon

From 8.1K App Store ratings

What we love

  • 🚀 Easy to use
  • 👍 Flexible and customizable
  • 🔍 Accurate food database
  • 💡 Helpful coaching and adjustments
  • 🤝 Responsive customer support

Room to improve

  • 🐛 Limited food database for some regions
  • 🤔 Strict adherence required for adjustments
  • 🤷‍♀️ Lack of exercise tracking integration

Function Health

From 25K App Store ratings

What we love

  • 🚀 Seamless process for blood tests and results
  • 📊 Comprehensive health insights and tracking
  • 🧠 Helpful clinician notes and recommendations
  • 👍 User-friendly and visually appealing app
  • 💰 Affordable compared to other options

Room to improve

  • 🔍 Lack of communication and support responsiveness
  • 🐛 Some bugs and usability issues in the app

Bugs and requests

Carbon

Reported bugs

2 issues
  • Occasional app crashes or freezes
  • Issues with resetting account data

Requested features

4 requests
  • Add water intake tracking
  • Improve barcode scanning functionality
  • Allow more flexibility in macro adjustments
  • Integrate with fitness trackers

Function Health

Reported bugs

2 issues
  • App sometimes redirects back to the home screen when trying to view results
  • Occasional typos and formatting issues in the app

Requested features

3 requests
  • More customization options in the app settings
  • Ability to print or export test results and recommendations
  • Specific supplement recommendations rather than broad suggestions

In-app purchases

9 purchases

Carbon

Subscriptions9
  • Monthly Subscription$11.991 Month
  • Monthly Subscription7 Days trial$11.991 Month
  • Monthly Subscription14 Days trial$11.991 Month
Show 6 more
  • Six Month Subscription$59.996 Months
  • Six Month Subscription7 Days trial$59.996 Months
  • Six Month Subscription14 Days trial$59.996 Months
  • Yearly Subscription$99.991 Year
  • Yearly Subscription7 Days trial$99.991 Year
  • Yearly Subscription14 Days trial$99.991 Year
None

Function Health

No in-app purchases

Questions

Is Carbon free?
Carbon is free to download, with in-app purchases available.
Is Function Health free?
Function Health is free to download, with no in-app purchases.
Which has better reviews, Carbon or Function Health?
Function Health is rated higher. Carbon averages 4.8 out of 5 from 8.1K ratings, while Function Health averages 4.9 from 25K ratings.
Do Carbon or Function Health have ads?
Neither Carbon nor Function Health shows ads.
Which is updated more often, Carbon or Function Health?
Carbon ships an update weekly, and Function Health weekly. Most recently, Carbon was updated on October 31, 2026 and Function Health on October 31, 2026.

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