Apple has reportedly been working for many years to bring noninvasive glucose monitoring to the Apple Watch. And according to a new report, the project might have recently hit a notable turning point. The ambitious initiative, first conceived during the Steve Jobs era, aims to develop sensors capable of detecting elevated blood sugar levels without requiring finger pricks or blood draws. This would be a game-changer for the millions of people worldwide who live with diabetes or prediabetes, offering a seamless way to track glucose levels directly from the wrist.
Apple Watch glucose monitoring project has a new leader, which some see as key sign of progress
This weekend in his Power On newsletter, Mark Gurman wrote about the future of the Apple Watch. He shared what to expect from watchOS 27 and provided an update on a key moonshot project in the works. According to Gurman, Apple recently shifted oversight of the glucose monitoring project from platform architecture chief Tim Millet to Zongjian Chen, the senior engineering leader overseeing the Advanced Technologies Group and hardware like modems. Some view the transition as a sign the work may finally be progressing to a point where Chen, known as someone who delivers, can ramp up development of the technology into an eventual consumer-grade offering.
This leadership transition was originally mentioned in a report last week, among many other Johny Srouji-driven shakeups. However, the context of how this move is being perceived within Apple is important. If Chen is known inside the company as “someone who delivers,” and this transition is seen as a sign of progress, then the transfer of responsibility from Millet to Chen could signal a key milestone being reached. That doesn’t mean we’ll see the Apple Watch gain noninvasive glucose monitoring this year, or even next year. It could still be several years away. However, this movement of responsibility is an encouraging sign of Apple making meaningful progress toward accomplishing its moonshot goal.
Understanding noninvasive glucose monitoring
Noninvasive glucose monitoring refers to the ability to measure blood sugar levels without breaking the skin. Current methods for people with diabetes typically involve finger-prick tests using a lancet and test strip, or continuous glucose monitors (CGMs) that use a tiny sensor inserted under the skin. Both methods are invasive and can be uncomfortable or inconvenient. Apple’s approach reportedly uses optical sensors—similar to the technology already found in the Apple Watch for heart rate and blood oxygen monitoring—to shine light through the skin and measure glucose levels in the interstitial fluid. The challenge has been to achieve accuracy comparable to traditional blood-based methods while keeping the sensor small and power-efficient enough for a wearable device.
The health implications are massive. According to the International Diabetes Federation, approximately 537 million adults worldwide have diabetes, and the number is expected to rise to 643 million by 2030. Even more people have prediabetes, a condition where blood sugar is elevated but not yet at diabetic levels. For these individuals, regular glucose monitoring is critical for managing diet, exercise, and medication. A noninvasive Apple Watch solution could dramatically improve compliance and quality of life, potentially reducing the risk of complications such as heart disease, kidney failure, and blindness. It could also serve as an early warning system for undiagnosed diabetes, alerting users to consult a doctor.
Apple’s long history with health sensors
Apple’s interest in health monitoring is well documented. The Apple Watch has evolved from a simple fitness tracker to a sophisticated health device capable of detecting atrial fibrillation, performing electrocardiograms (ECGs), measuring blood oxygen saturation, and monitoring sleep. The addition of noninvasive glucose monitoring would be the next logical step, completing a suite of metabolic sensors that could give users a comprehensive picture of their health. The company has filed numerous patents related to glucose monitoring, describing methods using spectroscopy, Raman spectroscopy, and absorption spectroscopy. Some patents even suggest using a combination of multiple light wavelengths to improve accuracy.
The project has been rumored for years, with reports dating back to as early as 2017. Apple has hired biomedical engineers and acquired startups in the field, such as RareLight in 2017 and possibly others. The technology has reportedly faced significant technical hurdles, particularly in achieving the required sensitivity and miniaturization. The recent leadership change may indicate that Apple has overcome some of these hurdles and is now ready to focus on productization.
Who are Tim Millet and Zongjian Chen?
Tim Millet is Apple’s vice president of platform architecture, responsible for the design of custom chips that power Macs, iPhones, and iPads. He has been with the company for over two decades and is known for his work on Apple’s transition to Apple Silicon. Overseeing the glucose monitoring project under Millet likely meant it was treated as a research endeavor within the hardware engineering group. Zongjian Chen, on the other hand, is a senior engineering leader who oversees the Advanced Technologies Group (ATG), which handles more futuristic projects like next-generation modems, wireless chips, and sensor technologies. Chen is known within Apple for delivering complex technologies on schedule, having previously led the development of Apple’s custom 5G modem and other connectivity chips. Moving the project to Chen’s group suggests a shift from pure research to a product-focused development phase.
The context of Johny Srouji’s broader reorganization adds weight to this move. Srouji, Apple’s senior vice president of Hardware Technologies, has been restructuring teams to better align with product timelines. The reassignment of the glucose monitoring project to Chen—who reports to Srouji—is part of that effort. Insiders say that Srouji wants to reduce the number of long-running projects that lack clear roadmaps to commercialization. By placing the glucose monitoring project under Chen, Apple is signaling that it expects tangible results in the coming years.
What this means for the Apple Watch timeline
Despite the encouraging news, consumers should not expect to see noninvasive glucose monitoring on the next Apple Watch. Even with a new leader, the technology still needs to pass regulatory approvals, something that can take years. The U.S. Food and Drug Administration (FDA) and international regulators will require rigorous clinical trials to prove the sensor’s accuracy and safety for medical use. Apple has experience with FDA clearance for the ECG and atrial fibrillation features, so the regulatory pathway is familiar, but glucose monitoring is arguably more complex because inaccurate readings could lead to dangerous insulin dosing errors.
Analysts suggest a realistic timeline is 2027–2028 for the first consumer iteration. Some believe Apple might initially release the feature as a non-medical wellness tool, similar to how blood oxygen saturation is presented as a general health metric rather than a diagnostic tool. This would allow Apple to bypass some regulatory hurdles while still providing value to users. However, the medical community would likely push for validation before relying on the data. Apple has also been in talks with health insurance companies and healthcare providers about integrating glucose data into broader health platforms.
Impact on the wearables market
If Apple succeeds, it would be a seismic shift in the wearables industry. Rivals like Samsung, Fitbit (Google), and Garmin have also explored noninvasive glucose monitoring, but none have brought a reliable solution to market. Apple’s ability to deliver such a feature would give the Apple Watch an unassailable competitive advantage, potentially driving millions of new upgrades from people with diabetes or those concerned about metabolic health. It could also open up new revenue streams through health subscriptions or partnerships with diabetes management platforms.
Beyond diabetes, noninvasive glucose monitoring could have broader applications for athletic performance, weight management, and general wellness. Athletes already use CGMs to optimize fueling during endurance events. The Apple Watch could democratize this data, making it accessible to anyone with a wrist. Moreover, trends in continuous glucose monitoring have exploded in the biohacking community, with people without diabetes using CGMs to understand how their bodies respond to different foods. Apple’s entry would legitimize and expand that market.
Technical challenges remain
Despite the optimism, significant technical hurdles remain. The primary challenge is achieving optical measurements that are reliable across different skin tones, tattoos, body fat percentages, and movement states. Apple has invested heavily in machine learning algorithms to correct for these variables, but the sensor still needs to work consistently while the user is sleeping, exercising, or wearing the watch loosely. Additionally, the sensor must consume very little power to maintain the Apple Watch’s all-day battery life. Any additional power draw from a continuous glucose sensor could require compromises in battery size or other features.
Another challenge is calibration. Most CGMs require periodic finger-stick calibrations to maintain accuracy. Apple’s goal is to eliminate the need for any calibration, making it truly noninvasive and maintenance-free. This is an extremely tall order. The company has been working on self-calibrating algorithms that use machine learning to adjust over time, but proving long-term stability is difficult. The leadership change to Chen, who has a track record of solving complex hardware and software integration problems, suggests that Apple believes these issues can be solved with enough engineering effort.
Wider implications for watchOS 27
In his newsletter, Gurman also touched on watchOS 27, the next major software update coming this fall. While he did not provide specifics, the timeline suggests that Apple is preparing for future hardware capabilities. The software stack for glucose monitoring would likely include new Health app APIs, visualizations, and notifications that prompt users when their levels are out of range. watchOS 27 could lay the groundwork for these features even if the hardware isn’t ready until a later model. Apple typically announces new health sensors at September events alongside new Apple Watch models, so speculating about watchOS 27 features tied to glucose monitoring is reasonable but premature.
Apple’s broader health ecosystem
The glucose monitoring project is part of a larger strategy by Apple to turn the Apple Watch into a medical-grade health device. The company has already released a research study on heart health and is conducting studies on mobility, hearing, and menstrual health. A glucose sensor would complement existing sensors to provide a holistic picture of metabolic health. Apple is also rumored to be working on a blood pressure monitor, though that project faces similar noninvasive challenges. Together, these sensors could position the Apple Watch as a primary tool for preventive healthcare, potentially reducing the burden on healthcare systems by catching issues early.
Privacy remains a cornerstone of Apple’s health strategy. All health data is encrypted on the device and in iCloud, and users control what data is shared with third-party apps. Glucose data would be especially sensitive, as it could reveal diabetes status and lifestyle habits. Apple’s strong privacy stance will be crucial for gaining trust from users and regulators alike.
In summary, while a noninvasive glucose monitoring Apple Watch is still years away, the recent leadership change from Tim Millet to Zongjian Chen is a positive signal that the project is maturing. With Chen’s reputation for delivering on complex technologies, Apple appears to be transitioning from research and development into product engineering. The journey from concept to consumer product remains fraught with technical and regulatory challenges, but the progress is undeniable. For those waiting for an Apple Watch that can truly monitor every aspect of their health, the wait might be worth it.
Source: 9to5Mac News