Samsung’s Antioxidant Index on Galaxy Watch8 transforms what once seemed like science fiction into everyday technology. In five seconds, a thumb scan returns precise carotenoid levels – the industry’s first measurable nutrition index.

By miniaturizing lab-grade sensor technology with exceptional accuracy, it turns your diet into an actionable metric for healthier aging. Establishing this new benchmark in wearable health tracking required years of intensive R&D, countless prototypes and unwavering grit.

Breaking New Ground in Nutrition Tracking

Back in 2018, Samsung saw a critical gap in wearables: we could count every step and calorie, yet there was no simple way to measure how our diet impacted our health. Deeper nutritional insights were locked behind expensive and time-consuming lab tests, out of reach for many people.

As people live longer, the focus is shifting from simply increasing lifespan to improving the quality of those additional years.

“In this context, antioxidation naturally gains attention as a method to slow down aging,” explains Dr. Hyojee Joung, a Seoul National University¹ public health nutrition expert who guided parts of the tech’s development. “If antioxidant management is neglected, Reactive Oxygen Species (ROS) accumulate in the body, increasing the risk of chronic diseases such as cardiovascular disease, diabetes and cancer.”

This realization made antioxidants the cornerstone of Samsung’s mission. Engineers and scientists focused on carotenoids – key antioxidants and proven indicators of fruit and vegetable intake – to create a device small enough to sit on your wrist, yet powerful enough to turn complex antioxidant data into simple, actionable health insights for everyone.

The first prototype of the spectroscopy-based antioxidant sensor.

A clinical-ready version of the sensor.

A prototype designed for use in skincare products.

Challenge #1: How to Shrink the Lab-Grade Sensor Technology

From day one, the dream of a nutrition-tracking wearable hit an immediate snag: traditional methods for measuring carotenoid levels like Raman spectroscopy are laser-based, non-invasive and precise, but rely on bulky machines that are far from wearable. So the team’s first mission was to shrink the lab-grade tech into a coin-sized sensor.

After seven years of rigorous testing and optimizing since the first prototype, the team developed the miniaturized sensor, a groundbreaking tech that combines multi-wavelength LEDs with a custom photodetector array to provide accurate carotenoid readings in a compact design.

“Our breakthrough was integrating reflectance spectroscopy with LEDs, which allowed us to miniaturize the technology while maintaining a high level of accuracy,” explains Jinyoung Park, a developer from Digital Health team at Samsung Electronics.

▲ Galaxy Watch8’s LED-PD sensor modules.

Unlike lasers, which emit a sharp, narrow wavelength, LEDs emit a broader wavelength range. By analyzing how much light is absorbed by the skin at multiple wavelengths through photodiodes², the watch estimates carotenoid levels with impressive accuracy. The advanced algorithms that continuously calibrate in real-time also support precision while delivering personalized insights to each user.

▲ The LED-PD prototype testbed at the back of Galaxy Watch8.

Challenge #2: How to Ensure the Tech Reaches Everyone

Creating a coin-sized carotenoid sensor was a major milestone, but the next challenge was ensuring it could work accurately and reliably across diverse skin types, making it truly accessible to everyone.

To overcome challenges like melanin interference in darker skin tones, Samsung’s engineers opted to use the fingertip for measurements since it has the least melanin across all ethnic groups. They also added simple tweaks, like light fingertip pressure during scans, which helps temporarily reduce blood flow and hemoglobin interference, making the results more accurate.

Extensive trials conducted at Samsung Medical Center³ included hundreds of participants, validating the sensor’s performance. This paved the way for a feature that seamlessly transitioned from the lab to users worldwide, offering an inclusive solution designed for everyday life.

How It Works

Carotenoids are the natural red, yellow and green pigments found in fruits and vegetables. Since our bodies can’t produce carotenoids on their own, the levels stored in the body offer a clear snapshot of how much fruit and vegetables someone has been eating.

This is where your Antioxidant Index score comes in, reflecting your carotenoid levels based on these categories:

• Very low: Less than 50% of the daily WHO recommendation of 400g per day.
• Low: Between 50%–100%.
• Optimal: 100% or more.

“Skin carotenoids metabolize and accumulate in tissues gradually, so short-term changes in fruit and vegetable intake won’t immediately appear in the score,” explains Dr. Hyojee Joung. “Our research shows that increased carotenoid intake leads to a meaningful rise in skin carotenoid levels after about one to two weeks, making the Index a valuable tool for tracking consistent, long-term dietary habits.”

Lifestyle factors like sleep quality, stress levels, and physical activity also influence the Index, making it a well-rounded indicator of overall health. Paired with other Galaxy Watch8 features like sleep coaching, activity tracking and Vascular Load monitoring, the Antioxidant Index offers a holistic view of your well-being, empowering smarter decisions for healthier aging.

▲ The Antioxidant Index feature measures carotenoid levels in seconds with the sensor on the back of the Galaxy Watch8 and provides additional nutritional insights on paired Galaxy smartphones.

Your Health, Reimagined

“New wearable sensors can play a role in helping people build healthy eating habits by tracking and encouraging sufficient daily intake of fruits and vegetables,” says Professor Yoonho Choi from Samsung Medical Center. “Over time, this simple practice can help prevent some cancers and other age-related diseases, making it a very effective way to support long-term health.”

Antioxidants are an emerging area of focus, but research has been limited due to the challenges of accurate measurement. Galaxy Watch8’s Antioxidant Index goes beyond current industry developments and delivers meaningful innovation.

Samsung’s ability to measure antioxidant levels with precision, acknowledged by experts as a benchmark for future research, represents a breakthrough in health monitoring. By helping users identify risks early and take proactive steps towards better health, Samsung is paving the way for a smarter, more proactive approach to wellness and redefining the role of wearables in preventative healthcare.

¹Seoul National University is a leading academic institution in South Korea.
²Photodiodes are semiconductor devices that convert light into electrical signals.
³Samsung Medical Center in Seoul, South Korea, is a leading medical institution known for its patient-centered care, advanced medical technologies, and specialized centers such as the Comprehensive Cancer and Proton Therapy Centers.

You too may have hummed your favourite movie song or counted from one to twenty when it all began. But as the days pass by, maybe you are becoming forgetful, and not washing your hands as regularly, and as well, as you should.

The World Health Organization has recommended frequent washing of hands among a slew of other measures to halt the spread of Covid-19. Hand wash is considered effective only when it lasts for full 20 seconds, according to healthcare professionals.

To make things easy, a small group of designers and developers from Samsung Research Institute-Bangalore, or SRI-B’s UX and wearable teams, worked round-the-clock over the last two weeks to come up with a solution that helps you keep healthy and safe.

Accordingly, SRI-B employees – mostly working remotely from their homes – built the ‘Hand Wash’ app – a wearable app for Galaxy Watch that prompts users to clean their hands, a key preventive attribute to stay safe.

The ‘Hand Wash’ app on Galaxy Watch helps users maintain hand hygiene by periodically reminding them about it and ensuring each wash is thorough for the duration of 20 seconds in line with WHO recommended best practices. The app comes with preset reminders which users can customize further based on their needs and schedule.

Also, each time the user initiates the wash sequence, the ‘Hand Wash’ app tracks the time and provides users with haptic feedback after 25 seconds of wash cycle. Five seconds are for turning on the tap and applying soap, while 20 seconds are for actual hand wash. The ‘Hand Wash’ app also notifies users if they miss any of scheduled pit stops to the wash basin!

The ‘Hand Wash’ app allows users to track their daily wash trends to build healthy habit over a period. The ‘Hand Wash’ app is further complimented by elegant watch face, which allows users to intuitively track their daily wash routine. Moreover, the watch face also shows the elapsed time since last wash to give users a sense of alertness about their hygiene in real time.

Galaxy Watch users can download the ‘Hand Wash’ app from the Galaxy Store.

We would love to hear your experience of using the ‘Hand Wash’ app. Your feedback will help us make the app better to help more users stay healthy and safe.

After all, when it comes to our health, prevention is always better than cure!

More Connected

To improve usability and enhance user engagement, S Health v.5.0 features a streamlined user interface. Now, in place of a main dashboard, the app’s supported health activities are neatly organized under three tabs – Me, Together and Discover – to help users more easily manage their fitness data.

Together is dedicated to social features. It’s where users can go to find extra motivation to achieve their goals. There, Challenges and Leaderboards encourage them to engage in healthy activities with friends to reach their fitness targets. Friendly one-on-one competitions like Step Challenges and the ability to share activity data on Facebook add further motivation, engaging users work out more actively together.

Whether a user walks, runs or cycles, S Health automatically detects the type of activity being engaged in and dutifully tracks the user’s progress. In all, 44 different activities are supported, including exercise bike and step machine sessions, as well as Pilates, lunges, crunches and squats.

Want a second opinion on a fitness program? Ask Experts is a new service that enables S Health users to connect and start Q&As with healthcare professionals anytime, anywhere via text, phone, or a simple search. With it, users will be able to ask questions, find answers and get helpful advice from professional health consultants local to their country. The service is currently available in Korea, and will expand to other countries in the near future*.

More Informative and Secure

Users will find dynamic content such as healthy living and workout tips, health information and relevant news under the Discover tab. Its content is geared to help users manage their health and stay motivated, covering major topics such as fitness, weight loss, sleep, nutrition, recipes, cardio health and other vital aspects of healthy living.

S Health has also been audited by an independent third-party firm for meeting requirements in the Health Insurance Portability and Accountability Act (HIPAA) – U.S. federal regulations requiring stringent measures to keep protected health information (PHI) secure. Furthermore, the service is backed by Samsung’s defense-grade security platform, Samsung Knox, to provide a higher level of protection and encryption with hardware-backed credential storage.

The Knox-supported S Health app can detect malware, rooting binary and unauthorized changes on users’ phones with the Knox framework. Once such hazards are detected, S Health will be rendered inaccessible.

Samsung Knox S Health support is compatible with S Health v.5.0 or higher and enabled on Samsung Galaxy devices starting with the Galaxy Note7. S Health v.5.0 can also be used on smartphones running on Android OS 4.4 and higher.

*Availability may vary by each country and market conditions.

**All functionality features, specifications and other product information provided in this document including, but not limited to, the benefits, design, pricing, components, performance, availability, and capabilities of the product are subject to change without notice or obligation.