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.

Samsung, India’s largest consumer electronics brand, has announced the launch of the third edition of ‘Walk-a-thon India’ Aug,25, a campaign designed to motivate India to get moving and to bolster the spirit of health and fitness in the country.

The registrations for the Walk-a-thon have begun and the challenge will run from August 1 to August 30, 2025, and is open exclusively to users across India. Participants simply need to opt in and complete 200,000 steps within the 30-day period to qualify for exciting rewards.

All finishers will be eligible for assured prizes. Three lucky winners will win the Galaxy Watch8, while the rest of the finishers will receive discount coupons worth up to INR 15000 on the all-new Galaxy Watch8. With the Walk-a-thon India, Samsung aims to make fitness rewarding and fun for everyone.

How to participate

The 30-day steps challenge will be hosted exclusively on the Samsung Health app, which is available on Samsung Galaxy smartphones. Participants can monitor their progress through a real-time leaderboard within the Samsung Health app, allowing them to compare their performance and stay motivated throughout the challenge. To qualify and be eligible for prizes, participants are required to complete a minimum of 200,000 steps over the 30-day duration. After completing the challenge, the finishers need to visit the Samsung Members app between September 5 to September 30, 2025,  to claim their reward.

Samsung Health App

Samsung Health is a global wellness and lifestyle platform that allows users to track a wide range of health metrics including steps, exercise, calorie intake, blood pressure, ECG, and sleep patterns. The app is designed to promote healthy living.

Galaxy Watch8

Built on the foundation of the Galaxy Watch Ultra’s cushion design, Galaxy Watch8 is 8.6 mm thin—offering a refined profile and snug, all-day comfort, thanks to its new Dynamic Lug System. Developed in close collaboration with Google, the Galaxy Watch8 series is the first smartwatch to come out of the box with Gemini, Google’s AI assistant, powered by Wear OS 6. Users can now go hands-free using natural voice commands to get things done on-the-go with the Galaxy Watch apps like Samsung Health, Calendar, Reminder and Clock.

Available in 40 mm and 44 mm sizes and finished in Graphite or Silver, Galaxy Watch8 features a dazzling Super AMOLED display with 3000 nits of peak brightness that ensures excellent visibility outdoors.

Under the hood, Galaxy Watch8 is powered by a 3 nm Exynos W1000 chipset powered by Wear OS 6 with Samsung’s One UI Watch 8 interface.  Galaxy Watch8 features advanced sensor technology and creates an intuitive AI-powered experience to help users fulfill a healthier, more connected life. Leveraging Samsung’s BioActive Sensor for continuous health tracking, the watches deliver real-time insights and instant rewards or alerts across sleep, stress, nutrition and activity, turning healthy intentions into immediate, motivating feedback. Plus, for the first time in a smartwatch, Galaxy Watch8 has introduced the Antioxidant Index, enabling users to measure carotenoid levels in just five seconds and make informed lifestyle choices for healthy aging.

Notably, the Watch 8 Series comes with a ‘Running Coach’ feature — a groundbreaking addition designed to elevate marathon training through personalized guidance. It begins with a 12-minute running test to analyze the user’s pre-training level, then provides a tailored program from a library of 160 options. During workouts, real-time voice coaching delivers instant feedback and motivation, while post-training insights offer detailed progress summaries and personalized recommendations — helping users optimize performance and achieve their fitness goals.

“We are committed to empowering billions of people to live healthier lives through our innovative technology,” said TM Roh, President and Acting Head of the Device eXperience (DX) Division at Samsung Electronics. “By combining purposeful design with advanced sensor technology and an intuitive AI-powered experience, the Galaxy Watch8 series serves as a starting point for a healthier, more connected life, making it easier than ever to take meaningful steps toward users’ well-being.”

Redesigned Inside and Out for Ultimate Wellness

By reimagining both form and function, the Galaxy Watch8 series delivers unmatched comfort alongside industry-leading performance, making it the ultimate companion for everyday wellness. The distinctive cushion design, which debuted with Galaxy Watch Ultra, now defines the entire Galaxy Watch lineup. To achieve the thinnest design yet, the internal structure of Galaxy Watch8 was completely reengineered and its component mounting capability has been improved by 30%, resulting in an 11% thinner design. Combined with the Dynamic Lug system, this design moves naturally with the wrist, providing greater comfort and improved stability² for a better fit and enhanced health-tracking accuracy.

Galaxy Watch8’s sleek profile is complemented by its exceptional performance. Even when you are outdoors under bright sunlight, the display is 50% brighter² with a peak brightness of 3,000nits for easy visibility, and the enhanced battery² ensures the watch can keep up with an active lifestyle. Moreover, the dual-frequency GPS provides more detailed and precise location results² while our most powerful 3nm processor delivers faster performance and greater power efficiency. With the groundbreaking BioActive Sensor that enables deeper and more accurate health insights, the Galaxy Watch8 series helps provide a holistic view of your health.

Motivation for Lasting Health Changes

Sleep is a window into your overall health and each restful night allows your body and mind to recover immediately the very next day. That’s why Samsung is continuously advancing the sleep experience, offering tailored sleep coaching, helping to create an optimal sleep environment, and even detecting moderate to severe signs of sleep apnea. On top of that, the Galaxy Watch8 series comes with new unique health features on the Samsung Health app³ that help you build healthier habits through instant, motivational insights – from sleep to nutrition and workout.

Bedtime Guidance⁴ can measure your circadian rhythm to suggest the optimal time to go to bed so you wake up refreshed the next morning. Vascular Load⁵ helps monitor the stress levels on your vascular system during sleep. Providing insights on various lifestyle factors including sleep, stress and activity, it helps you adopt a more comprehensive approach to managing your health.

Meanwhile, the Galaxy Watch8 series introduces Antioxidant Index⁶ for the first time in a smartwatch, enabling you to measure carotenoid levels in just five seconds and make informed lifestyle choices for healthy aging.

Whether you’re a novice or experienced runner, the Galaxy Watch8 series delivers personalized fitness insights to keep you motivated when you need it most. Running Coach⁷ calculates your fitness level from 1 to 10 and develops a tailored training plan complete with real-time guidance and motivational insights. With the updated Together feature, which now supports running, you can gamify your fitness journey by challenging friends and family.

If high level of stress persists, High Stress Alert will immediately signal so that you can take a break to help manage your stress levels in real-time. With Mindfulness Tracker, you can record your mood and receive guidance on breathing exercises to relieve your stress – all at once on your wrist.

Plus, the AI-powered Energy Score⁸ gives you a snapshot of your energy level, combining physical and mental energy metrics so you can have a healthier day, every day.

Easier Watch Interaction With Wear OS and Gemini

Developed in close collaboration with Google, the Galaxy Watch8 series is the first smartwatch to come out of the box with Gemini,⁹ Google’s AI assistant, and be powered by Wear OS 6. Go hands-free using natural voice commands to get things done on the go with your Galaxy Watch apps like Samsung Health, Calendar, Reminder and Clock. For example, you can ask Gemini to find a nearby cafe and text a friend to meet you there, all in one go. Or, if you’re ready to start your workout and you have a goal in mind, simply say, “Start a 30-minute run.” The watch seamlessly initiates the workout in Samsung Health.

In addition, thanks to the new One UI 8 Watch, the user interface is optimized for the size and shape of the watch face. The new Multi-Info Tiles provide easy access to health metrics, weather, events and more – all in a single, quick look. Moreover, the new Now Bar and depthless notifications ensure key activities are front and center.

Tailored To Match Every Lifestyle

Galaxy Watch8, Galaxy Watch8 Classic and the new Galaxy Watch Ultra are available for pre-order in select markets starting today, with general availability starting July 25.¹⁰

Featuring a sleek and minimalist design, Galaxy Watch8 is designed for everyday wellness. Available in 44mm or 40mm sizes and in Graphite or Silver, it provides comfort and style for daily activities. Meanwhile, Galaxy Watch8 Classic brings timeless sophistication to the wrist with modern features such as a rotating bezel and a quick button for added convenience. The Classic model measures 46mm and comes in Black and White. Plus, both models can be matched with a range of stylish bands¹¹ designed to suit diverse lifestyles.

For those who love outdoor adventures, Galaxy Watch Ultra is the most advanced and durable Galaxy Watch model yet. Available in four titanium finishes including the new Titanium Blue, it offers the longest battery life and the most robust performance in the lineup.

If you’re looking for a more discreet wearable that offers continuous health tracking, Galaxy Ring boasts superior comfort and up to seven days of battery life. Available in Titanium Black, Titanium Silver and Titanium Gold, the Galaxy Ring comes in sizes 5-15.¹¹

To learn more about Galaxy Watch8 and Galaxy Ring, please visit: www.samsungmobilepress.com, news.samsung.com/global, www.samsung.com/galaxy-watch or http://www.samsung.com/galaxy-ring.

Galaxy Watch8 Series Specifications

¹ Availability and  features may vary depending on market, model and the smartphone paired. 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.
² Compared to the previous Galaxy Watches.
³ Intended for general wellness and fitness purposes only. Not intended for use in detection, diagnosis, treatment, monitoring or management of any medical condition or disease. Any health-related information accessed through the device and/or application should not be treated as medical advice. Users should seek any medical advice from a physician. Certain features may vary by market, carrier, or the device paired.
⁴ Based on 3 days of sleep analysis of user’s circadian rhythm and sleep pressure.
⁵ Wearing a compatible Galaxy Watch is required when sleeping for at least 3 of the most recent 14 days.
⁶ To measure, the user should place the center of their finger on the sensor at the back of the Watch and hold it for 5 seconds. While Antioxidant Index can be measured using any finger, the thumb is recommended for the most accurate result. Repeat measurement due to uneven skin texture may lead to different results.
⁷ Prior to starting the coach program, taking a running level test and receiving a level designation is required.
⁸ Only available when user register a compatible Galaxy Watch or Galaxy Ring at least once.
⁹ Gemini mobile app available on select devices, languages, and countries. Requires compatible Wear OS watch to be connected to a compatible device. Check responses for accuracy. Internet connection and set up may be required. Features may differ depending on subscription and account. Results for illustrative purposes and may vary. Google and Gemini are trademarks of Google LLC.
¹⁰ Color and size availability may vary by market.
¹¹ Sold separately. Availability of watch bands may vary by market or carrier.
¹² Measured without health sensors.
¹³ Measured without band.
¹⁴ Battery life is based on results from internal lab tests for typical usage pattern scenarios conducted by Samsung. Actual battery life may vary depending on different usage patterns, device model, network environment and other factors. Typical value tested under third-party laboratory conditions. Typical value is the estimated average value considering the deviation in battery capacity among battery samples tested under the IEC 61960 standard.
¹⁵ Testing conducted by Samsung using pre-released version of Galaxy Watch8 and Galaxy Watch8 Classic (BT & LTE), each paired to a Samsung phone; all devices tested with prerelease software, Galaxy Watch Magnetic Fast Charging USB C Cable (EP-OL300), and Samsung 25W USB C Power Adapter (EP-TA800). Charge time varies according to region, settings, usage patterns and environmental factors; actual results may vary. Samsung 25W USB C Power Adapter (EP-TA800) sold separately.
¹⁶ Wear OS Powered by Samsung works with phones running Android 12 or later with more than 1.5GB of memory. Compatible devices may vary by market, carrier or device brand.
¹⁷ LTE connectivity only available in LTE models.
¹⁸ Galaxy Watch8 series has obtained MIL-STD 810H Certification: It has undergone a test that repeats from -20°C (1Hr) to 50°C (1Hr) for a total 6 hours.
¹⁹ Device activation is only available after connecting to a smartphone that supports Google Mobile Services. Compatible devices may vary by market, carrier or device brand.

Evolving into a personal health coach, the Galaxy Watch8 series helps users build tailored routines with tools for sleep guidance, running coaching, antioxidant and vascular load tracking. A soft-edged cushion design and built-in Gemini, Google’s AI assistant, offer both refined aesthetics and intuitive usability.

Samsung Newsroom got an exclusive early look at the Galaxy Watch8 series during Galaxy Unpacked 2025.

Bedtime Guidance: Say Goodbye to the Monday Blues

The Monday blues often stem not just from fatigue but from a disrupted weekend sleep cycle. To help recalibrate daily routines, Bedtime Guidance analyzes sleep patterns over the past three days and recommends an ideal time to wind down.

Vascular Load: Monitor Cardiovascular Health During Sleep

Vascular Load tracks stress on the vascular system while the user sleeps.

The feature incorporates related data — such as sleep duration, physical activity and stress levels — to offer a more holistic view of overall wellness.

Running Coach: Improve Performance With Real-Time Feedback

To help prevent injury while running, proper pacing and real-time, personalized feedback are essential. After a 12-minute run with the Galaxy Watch8 series, Running Coach analyzes performance data, categorizes running ability on a 10-level scale and generates a customized three- to five-week training program.

During runs, the feature provides personalized feedback guidance. Afterward, detailed workout summaries and motivational messages are shared.

Antioxidant Index: Track Carotenoid Levels in Seconds

Healthy aging starts from within. The Galaxy Watch8 series introduces the Antioxidant Index — a first-of-its kind smartwatch feature that measures carotenoid levels in the body.

By placing a thumb on the BioActive Sensor on the back of the watch for five seconds, users receive both a numerical score and a color-coded result representing their antioxidant status. The feature makes it easy to monitor aging-related health, offering intuitive insights into dietary and lifestyle habits. For example, a sky blue reading indicates a sufficient intake of carotenoid-rich foods like leafy greens and carrots.

Multimodal AI and One UI 8 Watch: Access Smarter Features

The Galaxy Watch8 series is the world’s first smartwatch to come equipped with Google’s Gemini. Even when hands are full, voice control allows users to operate key functions — offering intuitive support during workouts and daily routines.

For example, saying “start a 300-calorie circuit training workout” prompts Gemini to launch Samsung Health for seamless exercise tracking.

Debuting with this release, One UI 8 Watch introduces a redesigned tiles optimized for smaller displays — making essential information easier to view at a glance.

Ultra-Slim Cushion Design: Experience All-Day Comfort

The Galaxy Watch8 series brings innovation to hardware as well. The Galaxy Watch8 features the thinnest design in the series to date, with an ultra-slim 8.6-millimeter profile.

The lightweight build reduces strain on the wrist, while a cushion design — first introduced on the Galaxy Watch Ultra — gives the Galaxy Watch8 series a refined, modern look.

The Galaxy Watch8 series includes two models — Galaxy Watch8, with a minimalist design optimized for daily health tracking, and Galaxy Watch8 Classic, combining a rotating bezel and quick button with the appeal of an analog watch. In addition, the Galaxy Watch Ultra will be available in a new Titanium Blue color.

From morning to night, the Galaxy Watch8 series supports full-spectrum health management — spanning exercise to diet and beyond. Powered by AI, the Galaxy Watch8 series marks the beginning of a more personalized wellness journey.