The FDA Says Affected Dexcom Glucose Monitor Apps Stop Reporting Glucose Values Without Alerting the User When the Sensor's Transmitter Fails

On its pages of medical device recalls and early alerts, the US Food and Drug Administration carries one, current as of September 15, 2025, on a correction by Dexcom, Inc. to the apps for its G7 and ONE+ continuous glucose monitoring systems. The page says the G7 system provides "glucose readings, trends, alerts and notifications" that are displayed on its receiver or on a compatible smart device using the G7 apps. The page says the same of the ONE+ system and its apps.

The correction is to the apps. Parts of the page follow, not the whole.

A Missed Alert

The page describes a software design error in the apps. When the sensor's transmitter "encounters a hardware/firmware failure," the error leads to a missed "Sensor Failed" alert.

In that case, the page says, the affected app "ends the CGM sensor session, stops reporting glucose values" and shows the "Start Sensor" screen or a "No active sensor" message. It does this "without alerting the user."

Without that alert, the page says, a user may not know that glucose data, notifications, alerts and alarms have been missed for "extended periods." That "may result in a delay in treatment of prolonged episodes of severe hypoglycemia or hyperglycemia."

The app showed a "Start Sensor" screen where a "Sensor Failed" alert belonged.

The Most Serious Type

The recall is carried out through a software update, the page says, and the devices are not removed from where they are used or sold. A correction, not a removal.

"The FDA has identified this recall as the most serious type." The page warns that the device "may cause serious injury or death if you continue to use it without correction," and that use of the affected product "may cause serious adverse health consequences, including hypo/hyperglycemia and death." It also says "There have been no reported injuries or reports of death related to this issue."

A Mandatory Update

The affected versions are the G7 apps for Android, iOS and watchOS at version 2.8.0 or earlier, and the ONE+ apps for Android and iOS at version 1.4.0 or earlier. On July 24, 2025, the page says, Dexcom sent all affected customers an Urgent Medical Device Correction Notification.

As the page gives that notification, a design error was identified within G7 app version 2.8 "and all earlier versions," and within ONE+ app version 1.4 and all earlier versions. Upgrading is "mandatory," it says, and users "will not be able to use" those versions "after August 20, 2025."

The page does not say how the design error was found. For a monitor that carries the user's alerts and alarms, the alert that did not come was the one about its own failure.