FDA Authorizes First Combined Glucose and Ketone Monitor

Published August 27, 2026, after an FDA marketing authorization announced August 25.

The Food and Drug Administration authorized the first wearable device in the United States that continuously monitors ketone levels and the first device worldwide that tracks ketones and glucose together in one sensor. The Libre Duo 10 Day Continuous Dual Glucose Ketone Monitoring System is authorized for people age 2 and older who are living with diabetes.

The authorization creates a new monitoring option. It does not change how diabetes is diagnosed, and it does not show that the device prevents diabetic ketoacidosis, hospitalization, or death.

What the device measures

The sensor measures glucose and ketone levels in fluid just beneath the skin every minute during a 10-day wear period. Readings are sent wirelessly to a compatible smartphone, where the user can see current measurements and whether they are rising or falling. The system can also issue automatic alerts when ketone levels reach a concerning threshold.

Ketones are produced when the body uses fat instead of glucose for energy. In diabetes, an insulin shortage can allow ketones to build to dangerous levels and contribute to diabetic ketoacidosis, commonly called DKA. The FDA notes that ketone information should be interpreted together with glucose readings and symptoms.

This is different from traditional urine strips or blood ketone meters, which provide a reading at one point in time. The new sensor is designed to show the direction of change as well as the current measurement.

What the FDA reviewed

The FDA said its authorization was based on clinical and performance data from six studies enrolling more than 600 participants age 2 and older. Those studies evaluated the accuracy of both the glucose and ketone functions across a range of measurements. The agency said the device tracked clinically meaningful differences in ketone levels during the 10-day wear period, including elevated levels before the onset of DKA.

The FDA granted marketing authorization to Abbott Diabetes Care through the De Novo premarket review pathway for a new type of low- to moderate-risk device. The agency also established special controls covering requirements such as labeling and performance testing.

Abbott's US product page currently describes Libre Duo as "coming soon." That is the most specific primary-source availability statement published as of August 27. The device is prescription-only, and Abbott's safety information says sensor results and alerts must be used as directed and interpreted with other information.

Where laboratory testing still fits

A continuous sensor and a laboratory blood test answer different questions. The sensor shows short-interval glucose and ketone trends during wear. A fasting glucose test measures blood glucose at one point in time after a fast. An A1C test estimates average glucose over about three months. NIDDK lists laboratory blood tests, including fasting plasma glucose and A1C, among the tests used to diagnose diabetes and prediabetes.

The FDA authorization does not make a wearable reading a laboratory diagnosis. It also does not turn a diabetes risk panel into a substitute for continuous monitoring. The two approaches produce different information and should not be treated as interchangeable.

What not to overread

The authorization establishes that the device met the FDA's requirements for marketing under the De Novo pathway. It does not establish a population-level reduction in DKA emergencies, hospitalizations, or deaths. The FDA release summarizes accuracy and performance data, not a clinical-outcomes trial.

It also does not make continuous ketone monitoring a new universal standard for every person with diabetes. The public evidence supports a narrower conclusion: one combined sensor can now be marketed in the United States for continuous glucose and ketone monitoring in the authorized population.

This article is editorial commentary and is not medical advice. It has not been reviewed by a physician and should not be used to make decisions about diabetes diagnosis, ketone monitoring, medication, treatment, device use, or testing frequency.