A proposed class of consumers has launched a lawsuit against Dexcom Inc., accusing the medical device maker of misleading advertising and dangerous product defects tied to its popular G7 Continuous Glucose Monitoring (CGM) System — a device marketed as the “most accurate” glucose tracker approved by the U.S. Food and Drug Administration (FDA).

The complaint, filed Wednesday by Kelly Grisoli, alleges that Dexcom falsely assured users its monitors were safe and dependable, even as the FDA issued multiple Class I recalls — the agency’s most serious warning level, reserved for defects that can cause severe injury or death.

Recalls, Hidden Design Changes, and Mounting Complaints

According to the lawsuit, Dexcom quietly altered the sensor material in its G7 system in December 2023 without prior FDA approval. The unapproved change allegedly degraded the device’s accuracy, making readings unreliable and potentially life-threatening for diabetics who depend on the monitor to regulate their blood sugar.

Grisoli, who purchased the device for her diabetic son, said she quickly noticed defects. The sensors often failed before the promised 10-day lifespan, triggering false glucose readings and repeated hypoglycemic or hyperglycemic episodes. The complaint cites reports that at least one user died after a failed sensor falsely showed “normal” glucose levels.

Despite the malfunctions, Dexcom continued to promote the G7 as the gold standard in glucose tracking, claiming precision and safety unmatched by competitors. Grisoli contends those assurances were misleading — especially in light of FDA inspection findings that Dexcom had no adequate quality control procedures and had improperly implemented the design change.

Consumers Say They Were Left in Danger

The lawsuit paints a picture of a company that prioritized marketing over medical integrity. Grisoli said Dexcom’s frequent device failures forced her to buy replacement sensors at an unsustainable pace, prompting threats from the company to cut off sales when she exceeded monthly order limits.

Her complaint also accuses Dexcom of concealing defects, arguing that any statute of limitations should be tolled because consumers could not have reasonably discovered the problems. She seeks to represent a nationwide class of purchasers, as well as a California subclass, alleging violations of multiple state and federal consumer protection laws, including:

• Breach of express and implied warranty

• Negligent misrepresentation and fraudulent omission

• Unjust enrichment

• California’s CLRA, UCL, and False Advertising Law

• Song-Beverly Consumer Warranty Act

• Magnuson-Moss Warranty Act

“A Matter of Life and Death,” Attorneys Say

“For millions of people living with diabetes, technology isn’t optional — it’s a matter of life and death,” said C. Moze Cowper of Cowper Law LLP, one of the attorneys representing Grisoli. “Our lawsuit seeks accountability for Dexcom’s misleading claims about a medical device patients depend on every hour of every day.”

Co-counsel Adam J. Levitt of DiCello Levitt LLC added that medical device manufacturers must be held to the highest standards, emphasizing that transparency is crucial when lives are at risk.

The case also recalls previous lawsuits involving Dexcom’s earlier G6 model, which plaintiffs claimed produced inaccurate readings and failed to warn users during dangerous glucose drops.

No Immediate Response From Dexcom

Dexcom representatives did not immediately respond to requests for comment Friday. Counsel information for the company was unavailable at press time.

Grisoli is represented by C. Moze Cowper and Paige Miller of Cowper Law LLP and Adam J. Levitt of DiCello Levitt LLC.

The lawsuit marks another major test for Dexcom Glucose Monitor Tech, as questions mount about whether the company prioritized profit and reputation over the safety of the very patients its technology was designed to protect.