Dexcom G6 continuous glucose monitors are the subject of multiple class action lawsuits filed in 2025 following an FDA warning letter that found the company made unauthorized and dangerous changes to critical sensor components without proper regulatory approval. These changes resulted in sensors with significantly greater measurement variability than the approved versions, creating serious health risks for people with diabetes who rely on the devices to make insulin dosing decisions. For consumers who purchased G6 or G7 devices between January and November 2024, the lawsuits offer the potential to recover the full purchase price of their defective equipment.
The core issue involves a chemical compound coating used in a critical resistance layer of the sensors. Dexcom modified this component to secure a second source for the raw material, but the company made these changes without submitting new data to the FDA for approval—a violation of federal device regulations. When the FDA discovered the unauthorized modification during an inspection, clinical testing showed the new sensors had substantially higher variability in their readings compared to sensors made with the originally approved component.
Table of Contents
- What Manufacturing Defects Did the FDA Identify in Dexcom Sensors?
- How Does Sensor Variability Translate into Health Risks for Users?
- Who Filed the Consumer Class Action Lawsuit and What Does It Cover?
- What Are the Steps for Filing a Claim in the Dexcom Consumer Class Action?
- What Is the Securities Class Action and Who Should Be Aware of It?
- What Is Dexcom’s Response to These Allegations?
- What Is the Current Status of the Dexcom Class Actions and What Happens Next?
- Conclusion
- Frequently Asked Questions
What Manufacturing Defects Did the FDA Identify in Dexcom Sensors?
In March 2025, the FDA issued a formal warning letter to Dexcom documenting serious violations in the manufacturing of both G6 and G7 continuous glucose monitors. The agency found that the devices were “adulterated” due to quality system failures and unauthorized modifications made to a critical sensor component—specifically, a chemical compound coating in the resistance layer of the sensor. These changes were made without the required premarket clearance from the FDA, meaning Dexcom distributed sensors that had not been properly evaluated for safety and effectiveness with the new material.
The FDA’s inspection revealed that Dexcom had made these modifications as part of an effort to qualify a second source for raw materials and ensure a consistent supply to customers. However, rather than submitting the new data for FDA review before distributing the modified sensors, Dexcom proceeded to sell devices with the unauthorized component. Clinical studies comparing the two versions showed that sensors made with the new coating component had significantly greater variability in their readings—meaning they were less reliable and less accurate than the approved version. This is particularly dangerous for people with diabetes who use these continuous glucose monitors to decide when and how much insulin to inject.
How Does Sensor Variability Translate into Health Risks for Users?
The increased variability found in sensors using the unauthorized coating directly affects the ability of people with diabetes to manage their condition safely. A continuous glucose monitor is designed to provide real-time glucose readings so that users can make timely decisions about insulin administration. When the sensor’s readings are less accurate or more variable, users may inject too much insulin (risking dangerously low blood sugar) or too little insulin (failing to prevent high blood sugar and long-term complications).
Consider a person relying on their G6 sensor to detect a dangerous glucose drop at 2 a.m.—if the sensor reading is off by a significant margin due to the problematic coating, they may not receive the alert they need to prevent a medical emergency. The FDA’s warning identified that inaccuracies in the affected sensors create higher risks for users making diabetes treatment decisions based on unreliable readings. This is not a minor inconvenience—glucose management mistakes can lead to diabetic ketoacidosis, seizures, loss of consciousness, and long-term complications like organ damage. The limitation here is important to understand: even though many users may not have experienced obvious problems, the increased variability means the devices were functioning below the safety standard that was originally approved, creating a latent risk that persisted throughout 2024.
Who Filed the Consumer Class Action Lawsuit and What Does It Cover?
The law firm Wisner Baum filed a consumer class action lawsuit on September 29, 2025 in the U.S. District Court for the Southern District of California against Dexcom. The lawsuit was filed on behalf of all consumers who purchased Dexcom G6 or G7 devices between January 1, 2024 and November 30, 2024—the period when Dexcom was distributing sensors made with the unauthorized coating component.
The class action seeks refunds of the full purchase price of the defective devices for all eligible class members. To be eligible for the consumer class action, you must have purchased a Dexcom G6 or G7 device during this nine-month window. You don’t necessarily need to have experienced a specific problem with your sensor—the lawsuit is based on the fact that you purchased a device that failed to meet the FDA-approved standard due to Dexcom’s unauthorized modifications. The suit claims that consumers paid full price for devices without knowing they contained a problematic component that had not been properly evaluated by the FDA and was known to have greater measurement variability than the approved version.
What Are the Steps for Filing a Claim in the Dexcom Consumer Class Action?
If you purchased a Dexcom G6 or G7 device between January and November 2024, you should keep your proof of purchase—this might be a receipt, credit card statement, order confirmation email, or prescription documentation showing when you obtained the device. The lawsuit is still in early stages, so a formal claims process has not yet been established. However, once the lawsuit progresses and a settlement is reached (or a judgment is issued in the plaintiffs’ favor), a settlement administrator will be appointed to manage claims.
At that point, you will likely need to submit a claim form with proof of purchase and may need to provide additional information showing you purchased the device during the specified time period and that you are entitled to compensation. Unlike some settlement programs that require you to prove you actually suffered an injury, class actions like this one typically allow you to recover as long as you purchased the defective product during the class period—you generally don’t need to document that the sensor malfunctioned or caused you a specific problem. The tradeoff is that in a class action, your individual recovery will be divided among all class members, so the amount per person depends on how many claims are filed and what the total settlement amount is.
What Is the Securities Class Action and Who Should Be Aware of It?
Beyond the consumer lawsuit for refunds, a separate securities class action was filed on November 25, 2025 by Labaton Keller Sucharow LLP on behalf of Boston Retirement System and other investors who purchased DexCom stock. This lawsuit targets Dexcom’s failure to disclose the manufacturing defects and FDA warning letter, alleging that the company concealed material information from investors. The securities class covers persons and entities who purchased DexCom securities (stock) between January 8, 2024 and September 17, 2025. If you own or owned DexCom shares during this period, you may be an eligible member of the securities class action.
An important deadline to be aware of is December 26, 2025—this is the deadline for filing a lead plaintiff motion in the securities lawsuit. If you suffered significant losses on DexCom stock and want to participate in the case, you should contact an attorney well before this date. A lead plaintiff is a class member who is selected to represent the interests of all other investors in the lawsuit. This is particularly important because the amount of recovery in a securities class action depends on factors like stock price movements and the extent of investor losses. If DexCom’s stock dropped significantly after the FDA warning became public, investors who held shares at that time may be entitled to recover their losses.
What Is Dexcom’s Response to These Allegations?
Dexcom disputes the characterization that it made “unauthorized” changes to the sensor component. The company’s position is that it “qualified a second source for one of its raw materials, developed since 2021, to ensure an uninterrupted supply to customers.” In other words, Dexcom argues that sourcing the same material from a different supplier was a routine business decision, not an unauthorized modification requiring new FDA approval. The company maintains that the new supplier was producing the same chemical compound that had been approved by the FDA.
However, the FDA’s warning letter contradicts Dexcom’s framing. The agency found that the coating material from the second source was not equivalent to the originally approved version and that clinical testing showed greater variability in sensor performance. Notably, after the FDA warning, Dexcom ceased distribution of G7 sensors with the problematic component, effectively acknowledging the issue for new devices going forward. However, the company did not take action to recall or remediate the G6 sensors that had already been distributed during the class period, meaning people who purchased G6 devices in 2024 are still potentially using sensors with the higher-variability coating.
What Is the Current Status of the Dexcom Class Actions and What Happens Next?
As of now, both the consumer class action and the securities class action remain in early stages—no settlements have been reached, no trials have been scheduled, and no compensation has been awarded. The lawsuits are still in the discovery phase, where both sides gather evidence and information from each other. For the consumer class action, this process typically takes 12-24 months before a settlement is negotiated or a case goes to trial. For the securities class action, the immediate step is the lead plaintiff motion deadline of December 26, 2025.
Going forward, watch for notices about these lawsuits. If you are eligible (you purchased a G6 or G7 device between January and November 2024, or you held DexCom stock during the covered period), you should monitor the case’s progress so you do not miss deadlines for filing a claim once a settlement is finalized. Many consumers miss out on compensation simply because they don’t learn about the settlement until after the claims deadline has passed. Registering with case tracking websites or subscribing to updates from the law firms handling the case can help ensure you receive notice when claims are open.
Conclusion
The Dexcom G6 continuous glucose monitor class action represents a significant regulatory and legal reckoning for a device manufacturer that made unauthorized changes to critical sensor components and distributed millions of defective devices without proper FDA approval. The resulting sensors had greater measurement variability, creating real health risks for people with diabetes who depend on accurate readings to dose insulin safely. Two separate lawsuits—one for consumers seeking refunds and one for investors seeking to recover stock losses—have been filed, but neither has yet resulted in a settlement or judgment.
If you purchased a Dexcom G6 or G7 device in 2024 or held DexCom stock during the covered periods, you may be eligible for compensation. The key steps are to keep proof of your purchase or ownership and to stay informed about the litigation’s progress so you can file a timely claim when the settlement or trial is resolved. Given that these lawsuits are still in early stages, now is the time to document your eligible purchase and monitor the case for updates.
Frequently Asked Questions
I purchased a Dexcom G6 sensor in 2024, but I haven’t had any problems with it. Can I still file a claim?
Yes. In a class action lawsuit, you generally don’t need to prove that you suffered an injury or that the product malfunctioned. As long as you purchased a G6 or G7 device during the covered period (January-November 2024), you are eligible to claim a refund of your purchase price.
How much money will I receive from the class action?
The total amount available for distribution to class members depends on the settlement amount or judgment awarded in the lawsuit. This amount will be divided among all eligible claimants who file claims, so your individual recovery depends on how many people participate. Early estimates are not available because the case is still in early stages.
I bought a G6 sensor in December 2024. Am I included in the class action?
No, the consumer class action covers only purchases made between January 1, 2024 and November 30, 2024. If you purchased after November 30, 2024, you would not be eligible for the current class action, though you may have other options depending on your state’s consumer protection laws.
What does “unauthorized changes” mean? Did Dexcom do something illegal?
FDA regulations require manufacturers to submit data for approval before making material changes to a device’s components or manufacturing process. Dexcom made changes to a critical sensor coating component without first obtaining FDA approval for the new version, which violated federal law. Whether this rises to the level of criminal conduct would be a separate question investigated by prosecutors.
The FDA warning letter came out in March 2025, but Dexcom kept selling sensors until November 2024. How is that possible?
The timeline suggests that Dexcom was selling sensors with the unauthorized component throughout 2024, and the FDA discovered the problem during an inspection that led to the March 2025 warning letter. The FDA did not catch the violation in real-time, which is why consumers purchased the defective sensors without knowing about the issue.
Should I stop using my G6 sensor from 2024?
That is a medical decision to discuss with your endocrinologist or diabetes care provider. While the sensors with the problematic coating have greater variability, they were still providing glucose readings. Your doctor can advise whether to continue using your current sensor, switch to an alternative continuous glucose monitor, or wait for a replacement option.