Smartwatches are getting better at health tracking every year. They can measure heart rate, track sleep, record workouts, detect some rhythm irregularities, and in some models record a single-lead ECG. Because of that, many people now ask the next big question: can a smartwatch measure blood glucose, and will it soon replace a glucose meter or continuous glucose monitor?
The most accurate answer today is clear: smartwatches may become useful for glucose awareness in the future, but they do not currently replace approved glucose monitors.
As of now, the U.S. FDA has not authorized, cleared, or approved any smartwatch or smart ring that measures or estimates blood glucose on its own without piercing the skin. The FDA specifically warns people not to use smartwatches or smart rings that claim to measure blood glucose non-invasively, because inaccurate readings can lead to dangerous treatment decisions.
For people with diabetes, this distinction is critical. Blood glucose data is not just “wellness information.” It can affect insulin dosing, medication decisions, food intake, exercise planning, and urgent hypoglycemia treatment.
Some watches can display glucose data from a connected CGM app. Some companies are researching non-invasive glucose monitoring. Some devices may claim to estimate glucose without a sensor under the skin. But there is an important difference between these three things:
A smartwatch that displays CGM data is not measuring glucose by itself.
A research prototype is not the same as an approved consumer medical device.
A smartwatch or ring that claims non-invasive glucose measurement is not automatically safe, accurate, or medically approved.
The FDA warning is very direct: smartwatches and smart rings that claim to measure blood glucose without piercing the skin have not been authorized, cleared, or approved by the FDA.
So the safest answer is this:
No, smartwatches do not currently replace approved glucose meters or CGMs for reliable glucose monitoring.
ECG is different, but still more direct: the watch records electrical activity from the heart through electrodes for a short period.
Glucose is much harder.
Blood glucose monitoring requires measuring the concentration of glucose in blood or interstitial fluid. Traditional glucose meters use a blood sample from a finger prick. Continuous glucose monitors use a tiny sensor inserted under the skin to measure glucose in the interstitial fluid.
A smartwatch sitting on top of the skin does not have direct access to blood glucose. That is why non-invasive glucose monitoring is such a difficult technical problem.
Glucose measurement is difficult because:
Apple has reportedly been researching non-invasive glucose monitoring for years, but as of now, Apple Watch does not provide direct glucose readings. Recent reporting still suggests that non-invasive Apple Watch glucose monitoring is unlikely to arrive for several more years, if it ever becomes practical at consumer scale.
Apple Watch can be useful for health awareness. It can track activity, heart rate, sleep, and some heart rhythm data. It may also work with third-party health apps. But it does not replace a glucose meter or CGM.
The accurate wording is:
Apple Watch can support general health tracking, but it does not currently measure blood glucose or replace a glucose monitor.
Samsung watches may support health features such as heart rate, sleep, ECG in supported regions, and body composition estimates. They may also connect with health apps. But they do not currently provide approved, standalone, non-invasive glucose readings that can replace a glucose monitor.
If a smartwatch displays glucose values from a CGM app, the glucose measurement is coming from the CGM sensor, not from the watch itself.
This distinction matters. The watch may be the screen, but the CGM is the measuring device.
The FDA warning applies to any smartwatch or smart ring that claims to measure or estimate blood glucose values on its own without piercing the skin. The FDA states that these devices have not been authorized, cleared, or approved for this purpose.
This does not mean every wearable is useless. It means users should not rely on unapproved non-invasive glucose claims for medical decisions.
If a device claims “no needle blood sugar monitoring” or “glucose measurement without a sensor” and it is not an approved glucose monitoring device, it should be treated very carefully.
A continuous glucose monitor, or CGM, is a glucose monitoring system that uses a sensor placed under the skin. It measures glucose in interstitial fluid and sends readings to a receiver, phone, or sometimes a compatible watch.
The key difference is simple:
A smartwatch may show glucose data. A CGM measures glucose.
Popular CGM systems include devices from Dexcom and Abbott FreeStyle Libre. For example, the FDA cleared Dexcom Stelo in 2024 as the first over-the-counter continuous glucose monitor in the United States, intended for adults who do not use insulin, including people with type 2 diabetes treated without insulin or people who want to understand how diet and exercise affect glucose.
Abbott’s FreeStyle Libre systems also provide real-time glucose readings through a sensor worn on the body, with readings delivered to a smartphone or reader depending on the system and region.
In the future, smartwatches may become more useful for glucose trend awareness. They may help detect patterns, estimate risk, or integrate with CGMs more smoothly. But replacing glucose monitors is a much bigger challenge.
For smartwatches to replace glucose monitors, they would need to:
A smartwatch glucose feature that is “interesting” is not enough. It must be accurate enough to guide real health decisions, especially for people at risk of hypoglycemia or hyperglycemia.
If a person with diabetes receives a falsely high glucose reading, they may take too much insulin or make unnecessary medication changes. If they receive a falsely low reading, they may eat unnecessary carbohydrates or miss needed treatment. In people using insulin, these mistakes can become serious quickly.
The FDA warns that inaccurate glucose readings from unauthorized smartwatches or rings could lead to errors in diabetes management, including taking the wrong dose of insulin or other medication.
This is why glucose monitoring should not be treated as a casual wellness feature.
For people with diabetes, accuracy is not optional.
A smartwatch can sometimes display glucose data from a CGM system. In that case, the smartwatch is acting as a convenient display, not the glucose sensor itself.
This can be very helpful because users may be able to glance at their wrist instead of opening a phone or reader. For people managing glucose throughout the day, that convenience can improve awareness and reduce friction.
A smartwatch can help display:
CGMs measure glucose in interstitial fluid, not directly in blood. There can be a lag between blood glucose and interstitial glucose, especially during rapid changes after meals, exercise, or insulin use.
Many CGM users may still need a finger-prick test in certain situations, depending on the device, symptoms, and medical advice.
Finger-prick glucose meters may still be useful when:
This is especially important for:
For example, CGMs can help people see how glucose responds to meals, sleep, exercise, stress, and medication. Over-the-counter CGMs such as Dexcom Stelo are designed for adults who do not use insulin, including people with type 2 diabetes not using insulin or people who want to understand how diet and exercise affect glucose.
Wearable glucose data may help with:
This is the “holy grail” of glucose technology. If it worked reliably, it could make glucose monitoring easier, more comfortable, and more widely accessible.
Researchers have explored methods such as optical sensing, spectroscopy, sweat analysis, tear fluid, skin measurements, and other biosignals. The challenge is that glucose is difficult to isolate accurately from the surface of the skin.
Non-invasive glucose monitoring must solve several problems:
Smartwatch
A smartwatch is useful for health awareness, activity tracking, heart rate, sleep, and displaying data from other devices. It does not currently replace approved glucose monitoring.
CGM
A continuous glucose monitor uses a sensor under the skin to measure glucose trends throughout the day and night. It is useful for ongoing glucose tracking and can reduce the need for frequent finger-prick checks for many users.
Finger-prick glucose meter
A finger-prick meter measures blood glucose from a small blood sample. It is still useful for confirmation, backup testing, and people who do not use CGM.
For glucose management, smartwatches are support tools. CGMs and glucose meters are measurement tools.
Before trusting any glucose reading, ask:
The FDA specifically recommends avoiding smartwatches and smart rings that claim to measure blood glucose without piercing the skin.
Large technology companies are clearly interested in glucose monitoring. Apple has been rumored to be working on non-invasive glucose technology for years. Other companies are also exploring wearable biosensors, smart rings, optical systems, and metabolic tracking.
But glucose monitoring is not just another smartwatch feature. It is a medical function with high safety requirements.
To become a true replacement for glucose meters or CGMs, a smartwatch would need regulatory approval, strong clinical accuracy, and safe performance across real-world users.
That may happen in the future, but it has not happened yet.
Use a smartwatch for:
A smartwatch may track activity, heart rate, sleep, ECG, and even display glucose data from a CGM. But it does not directly measure blood glucose in the way an approved glucose meter or CGM does.
The future may bring better non-invasive glucose technology. If that happens, smartwatches could become much more important in glucose tracking. But today, glucose monitoring still requires approved tools such as finger-prick glucose meters or continuous glucose monitors.
For people with diabetes, this matters. Glucose readings can guide medication, food, exercise, and urgent treatment decisions. Until smartwatch glucose monitoring is clinically validated and approved, it should not be used as a replacement for a glucose meter or CGM.
The most accurate answer today is clear: smartwatches may become useful for glucose awareness in the future, but they do not currently replace approved glucose monitors.
As of now, the U.S. FDA has not authorized, cleared, or approved any smartwatch or smart ring that measures or estimates blood glucose on its own without piercing the skin. The FDA specifically warns people not to use smartwatches or smart rings that claim to measure blood glucose non-invasively, because inaccurate readings can lead to dangerous treatment decisions.
For people with diabetes, this distinction is critical. Blood glucose data is not just “wellness information.” It can affect insulin dosing, medication decisions, food intake, exercise planning, and urgent hypoglycemia treatment.
Can Smartwatches Measure Blood Glucose?
Today, mainstream smartwatches do not directly measure blood glucose like a finger-prick glucose meter or a continuous glucose monitor.Some watches can display glucose data from a connected CGM app. Some companies are researching non-invasive glucose monitoring. Some devices may claim to estimate glucose without a sensor under the skin. But there is an important difference between these three things:
A smartwatch that displays CGM data is not measuring glucose by itself.
A research prototype is not the same as an approved consumer medical device.
A smartwatch or ring that claims non-invasive glucose measurement is not automatically safe, accurate, or medically approved.
The FDA warning is very direct: smartwatches and smart rings that claim to measure blood glucose without piercing the skin have not been authorized, cleared, or approved by the FDA.
So the safest answer is this:
No, smartwatches do not currently replace approved glucose meters or CGMs for reliable glucose monitoring.
Why Is Blood Glucose Harder Than Heart Rate or ECG?
Heart rate is relatively easy for a smartwatch to estimate because the watch can detect blood volume changes at the wrist using optical sensors.ECG is different, but still more direct: the watch records electrical activity from the heart through electrodes for a short period.
Glucose is much harder.
Blood glucose monitoring requires measuring the concentration of glucose in blood or interstitial fluid. Traditional glucose meters use a blood sample from a finger prick. Continuous glucose monitors use a tiny sensor inserted under the skin to measure glucose in the interstitial fluid.
A smartwatch sitting on top of the skin does not have direct access to blood glucose. That is why non-invasive glucose monitoring is such a difficult technical problem.
Glucose measurement is difficult because:
- Glucose concentration changes throughout the day.
- Food, stress, exercise, sleep, illness, and medication can shift glucose levels.
- Skin thickness, hydration, temperature, sweat, and motion can affect sensor signals.
- Interstitial glucose and blood glucose are related but not identical.
- Small errors can be clinically important for people using insulin.
- A false low or false high reading can lead to dangerous decisions.
Does Apple Watch Measure Blood Glucose?
No. Apple Watch does not currently measure blood glucose.Apple has reportedly been researching non-invasive glucose monitoring for years, but as of now, Apple Watch does not provide direct glucose readings. Recent reporting still suggests that non-invasive Apple Watch glucose monitoring is unlikely to arrive for several more years, if it ever becomes practical at consumer scale.
Apple Watch can be useful for health awareness. It can track activity, heart rate, sleep, and some heart rhythm data. It may also work with third-party health apps. But it does not replace a glucose meter or CGM.
The accurate wording is:
Apple Watch can support general health tracking, but it does not currently measure blood glucose or replace a glucose monitor.
Does Samsung Galaxy Watch Measure Blood Glucose?
No mainstream Samsung Galaxy Watch currently replaces a glucose meter or CGM for direct glucose monitoring.Samsung watches may support health features such as heart rate, sleep, ECG in supported regions, and body composition estimates. They may also connect with health apps. But they do not currently provide approved, standalone, non-invasive glucose readings that can replace a glucose monitor.
If a smartwatch displays glucose values from a CGM app, the glucose measurement is coming from the CGM sensor, not from the watch itself.
This distinction matters. The watch may be the screen, but the CGM is the measuring device.
What About Smart Rings That Claim to Measure Glucose?
Smart rings should be treated with the same caution as smartwatches.The FDA warning applies to any smartwatch or smart ring that claims to measure or estimate blood glucose values on its own without piercing the skin. The FDA states that these devices have not been authorized, cleared, or approved for this purpose.
This does not mean every wearable is useless. It means users should not rely on unapproved non-invasive glucose claims for medical decisions.
If a device claims “no needle blood sugar monitoring” or “glucose measurement without a sensor” and it is not an approved glucose monitoring device, it should be treated very carefully.
What Is the Difference Between a Smartwatch and a CGM?
A smartwatch is a wearable computer. It can track activity, heart rate, sleep, and other signals. It may also display health data from other devices.A continuous glucose monitor, or CGM, is a glucose monitoring system that uses a sensor placed under the skin. It measures glucose in interstitial fluid and sends readings to a receiver, phone, or sometimes a compatible watch.
The key difference is simple:
A smartwatch may show glucose data. A CGM measures glucose.
Popular CGM systems include devices from Dexcom and Abbott FreeStyle Libre. For example, the FDA cleared Dexcom Stelo in 2024 as the first over-the-counter continuous glucose monitor in the United States, intended for adults who do not use insulin, including people with type 2 diabetes treated without insulin or people who want to understand how diet and exercise affect glucose.
Abbott’s FreeStyle Libre systems also provide real-time glucose readings through a sensor worn on the body, with readings delivered to a smartphone or reader depending on the system and region.
Will Smartwatches Replace Glucose Monitors?
Today, the answer is no.In the future, smartwatches may become more useful for glucose trend awareness. They may help detect patterns, estimate risk, or integrate with CGMs more smoothly. But replacing glucose monitors is a much bigger challenge.
For smartwatches to replace glucose monitors, they would need to:
- Measure glucose accurately without a blood sample or skin sensor.
- Work across different skin types, ages, body compositions, and health conditions.
- Remain accurate during movement, sweating, sleep, exercise, and temperature changes.
- Detect both high and low glucose safely.
- Meet medical-device accuracy standards.
- Be accepted by regulators and clinicians.
- Be safe enough for people using insulin or glucose-lowering medication.
A smartwatch glucose feature that is “interesting” is not enough. It must be accurate enough to guide real health decisions, especially for people at risk of hypoglycemia or hyperglycemia.
Why Inaccurate Glucose Readings Can Be Dangerous
Inaccurate glucose readings can be much more dangerous than inaccurate step counts or sleep estimates.If a person with diabetes receives a falsely high glucose reading, they may take too much insulin or make unnecessary medication changes. If they receive a falsely low reading, they may eat unnecessary carbohydrates or miss needed treatment. In people using insulin, these mistakes can become serious quickly.
The FDA warns that inaccurate glucose readings from unauthorized smartwatches or rings could lead to errors in diabetes management, including taking the wrong dose of insulin or other medication.
This is why glucose monitoring should not be treated as a casual wellness feature.
For people with diabetes, accuracy is not optional.
Can a Smartwatch Display Glucose Data from a CGM?
Yes. This is where smartwatches are already useful.A smartwatch can sometimes display glucose data from a CGM system. In that case, the smartwatch is acting as a convenient display, not the glucose sensor itself.
This can be very helpful because users may be able to glance at their wrist instead of opening a phone or reader. For people managing glucose throughout the day, that convenience can improve awareness and reduce friction.
A smartwatch can help display:
- Current glucose value
- Glucose trend direction
- Alerts from a CGM app
- Time-in-range summaries
- Historical patterns
- Exercise or activity context
Are CGMs Replacing Finger-Prick Glucose Meters?
CGMs have already reduced the need for routine finger-prick checks for many users. However, finger-prick glucose meters still have a role.CGMs measure glucose in interstitial fluid, not directly in blood. There can be a lag between blood glucose and interstitial glucose, especially during rapid changes after meals, exercise, or insulin use.
Many CGM users may still need a finger-prick test in certain situations, depending on the device, symptoms, and medical advice.
Finger-prick glucose meters may still be useful when:
- Symptoms do not match CGM readings.
- Glucose is changing rapidly.
- A sensor may be inaccurate or failing.
- A backup reading is needed.
- A healthcare professional recommends confirmation.
- The person does not use a CGM.
Who Should Not Rely on a Smartwatch for Glucose?
People with diabetes should not rely on a smartwatch or smart ring that claims to measure glucose without an approved sensor.This is especially important for:
- People using insulin
- People at risk of hypoglycemia
- People with type 1 diabetes
- People with type 2 diabetes using glucose-lowering medication
- Pregnant people with gestational diabetes
- People who need glucose readings for treatment decisions
- People whose doctor has recommended finger-prick testing or CGM use
Who Might Benefit from Wearable Glucose Data?
Wearable glucose data can be useful when it comes from an approved CGM or biosensor.For example, CGMs can help people see how glucose responds to meals, sleep, exercise, stress, and medication. Over-the-counter CGMs such as Dexcom Stelo are designed for adults who do not use insulin, including people with type 2 diabetes not using insulin or people who want to understand how diet and exercise affect glucose.
Wearable glucose data may help with:
- Understanding post-meal glucose spikes
- Seeing the effect of exercise
- Tracking overnight glucose trends
- Improving time in range
- Sharing data with a healthcare professional
- Building better habits around food, sleep, and activity
What Is Non-Invasive Glucose Monitoring?
Non-invasive glucose monitoring means measuring glucose without piercing the skin.This is the “holy grail” of glucose technology. If it worked reliably, it could make glucose monitoring easier, more comfortable, and more widely accessible.
Researchers have explored methods such as optical sensing, spectroscopy, sweat analysis, tear fluid, skin measurements, and other biosignals. The challenge is that glucose is difficult to isolate accurately from the surface of the skin.
Non-invasive glucose monitoring must solve several problems:
- Detecting glucose signal through skin
- Separating glucose from other biological signals
- Remaining accurate during movement
- Working across different skin tones and body types
- Handling hydration, sweat, temperature, and pressure changes
- Proving safety and accuracy in clinical studies
Smartwatch vs CGM vs Finger-Prick Meter
Here is the practical difference:Smartwatch
A smartwatch is useful for health awareness, activity tracking, heart rate, sleep, and displaying data from other devices. It does not currently replace approved glucose monitoring.
CGM
A continuous glucose monitor uses a sensor under the skin to measure glucose trends throughout the day and night. It is useful for ongoing glucose tracking and can reduce the need for frequent finger-prick checks for many users.
Finger-prick glucose meter
A finger-prick meter measures blood glucose from a small blood sample. It is still useful for confirmation, backup testing, and people who do not use CGM.
For glucose management, smartwatches are support tools. CGMs and glucose meters are measurement tools.
What Should You Do If a Watch Claims to Measure Blood Sugar?
If a smartwatch or ring claims to measure blood sugar without a sensor, treat the claim carefully.Before trusting any glucose reading, ask:
- Is the device approved or cleared by a regulator for glucose measurement?
- Does it use a real glucose sensor?
- Is it intended for medical use or only wellness?
- Does it require calibration?
- Can it be used for treatment decisions?
- Does your doctor recommend it?
- Are there clinical accuracy studies?
The FDA specifically recommends avoiding smartwatches and smart rings that claim to measure blood glucose without piercing the skin.
Will Apple, Samsung, or Other Brands Eventually Solve It?
Possibly, but not yet.Large technology companies are clearly interested in glucose monitoring. Apple has been rumored to be working on non-invasive glucose technology for years. Other companies are also exploring wearable biosensors, smart rings, optical systems, and metabolic tracking.
But glucose monitoring is not just another smartwatch feature. It is a medical function with high safety requirements.
To become a true replacement for glucose meters or CGMs, a smartwatch would need regulatory approval, strong clinical accuracy, and safe performance across real-world users.
That may happen in the future, but it has not happened yet.
The Best Current Approach
The best current approach is to use the right tool for the right purpose.Use a smartwatch for:
- Activity tracking
- Heart rate trends
- Sleep tracking
- General health awareness
- Displaying approved CGM data when supported
- Continuous glucose trends
- Time-in-range tracking
- Glucose pattern awareness
- Reducing routine finger-prick checks when appropriate
- Sharing glucose data with a healthcare professional
- Direct blood glucose checks
- Backup testing
- Confirming symptoms
- Situations where CGM readings may not match how you feel
- Following your clinician’s instructions
Frequently Asked Questions
Can a smartwatch measure blood glucose?
No mainstream smartwatch currently replaces an approved glucose meter or CGM for direct glucose monitoring. Some watches may display glucose data from a CGM, but the watch itself is not measuring glucose.
Does Apple Watch measure blood glucose?
No. Apple Watch does not currently measure blood glucose. Apple has reportedly researched non-invasive glucose monitoring, but the feature is not available as a standard Apple Watch glucose monitor.
Does Samsung Galaxy Watch measure blood glucose?
No. Samsung Galaxy Watch does not currently replace a glucose meter or CGM for direct glucose monitoring. It may support health tracking and app integrations, but it does not provide approved standalone glucose readings.
Can a smartwatch replace a CGM?
Not today. A smartwatch may display CGM data, but it does not replace the CGM sensor. The CGM is the device measuring glucose.
Are non-invasive glucose watches accurate?
No smartwatch or smart ring has been authorized, cleared, or approved by the FDA to measure or estimate blood glucose on its own without piercing the skin. Users should not rely on such devices for diabetes management.
Can people without diabetes use a CGM?
Some CGMs are now available over the counter in certain markets. In the U.S., Dexcom Stelo was cleared by the FDA for adults 18 and older who do not use insulin, including people with diabetes treated without insulin or people who want to understand how diet and exercise affect glucose.
What should I use for accurate glucose monitoring?
For accurate glucose monitoring, use an approved finger-prick glucose meter or an approved CGM. People with diabetes should follow their healthcare professional’s advice on which device to use and how often to check glucose.
Conclusion
Smartwatches are powerful tools for health awareness, but they do not currently replace glucose monitors.A smartwatch may track activity, heart rate, sleep, ECG, and even display glucose data from a CGM. But it does not directly measure blood glucose in the way an approved glucose meter or CGM does.
The future may bring better non-invasive glucose technology. If that happens, smartwatches could become much more important in glucose tracking. But today, glucose monitoring still requires approved tools such as finger-prick glucose meters or continuous glucose monitors.
For people with diabetes, this matters. Glucose readings can guide medication, food, exercise, and urgent treatment decisions. Until smartwatch glucose monitoring is clinically validated and approved, it should not be used as a replacement for a glucose meter or CGM.
Sources
- FDA — Do Not Use Smartwatches or Smart Rings to Measure Blood Glucose Levels
- FDA — FDA Clears First Over-the-Counter Continuous Glucose Monitor
- Dexcom — Stelo by Dexcom First Glucose Biosensor Cleared by FDA as Over-the-Counter
- Abbott FreeStyle Libre — Continuous Glucose Monitoring
- Harvard Health — FDA warning against smart gadgets for blood sugar monitoring
- Reuters — FDA warning on smartwatches claiming blood glucose measurement
- AP News — FDA warns against smartwatches and rings that claim to measure blood sugar without needles
