Dexcom warns stolen G7 sensors were resold after failing quality checks

Image courtesy of Dexcom Inc

For CGM users who rely on sensors overnight, during exercise or while using hybrid-closed loop systems, the idea that rejected sensors could re-enter circulation has triggered concern across diabetes forums and social media groups.

The incident has also renewed discussion around counterfeit CGM sensors, unofficial diabetes technology resale markets and how secure medical device supply chains really are once products leave authorised distribution channels.

What Dexcom says happened

According to Dexcom, the affected G7 sensors had already been removed from normal commercial distribution because they did not meet internal quality standards during testing.

The company says the sensors were classified as scrap stock and were meant to be destroyed and recycled through a third-party disposal vendor. Instead, Dexcom alleges that two affected lots were stolen during the disposal process and later sold onwards through unofficial resale networks.

Dexcom later traced the products back to Pharmsource LLC, which the company says is not an authorised Dexcom distributor.

The two affected lot numbers identified by Dexcom are:

• 1725204004
• 1725069002

Dexcom says the sensors were never intended for patient use because they failed internal manufacturing or quality checks.

Reports linked to the affected lots suggest one may carry an increased risk of incomplete sterilisation and possible skin infection, while another may have an elevated risk of deployment failure or an inability to generate glucose readings.

Australia’s Therapeutic Goods Administration has also published notices connected to the affected lots, stating the sensors had been marked for disposal following issues involving sterilisation and deployment performance during testing.

Dexcom has not suggested that standard pharmacy-distributed G7 stock is broadly affected by the incident.

CGM trust and reliability concerns

The timing is also notable because Dexcom itself has recently acknowledged that reliability and trust remain some of the most important issues for CGM users as the company develops future generations of sensors and adaptive algorithms.

Recent presentations around Dexcom’s next-generation technology have focused heavily on improving consistency, reducing signal problems and increasing user confidence in CGM performance. You can read more in our article on adaptive sensing and future CGM accuracy improvements.

At the same time, Dexcom has already faced growing scrutiny over manufacturing quality and CGM reliability during the past two years.

In 2025, the FDA issued a warning letter connected to manufacturing and quality control concerns involving Dexcom sensors.

Separate recalls and corrections involving receivers and app alerts have also affected some Dexcom systems.

Meanwhile, diabetes forums continue to see discussion about:

• sensor failures
• false readings
• signal loss
• premature shutdowns
• missed alerts
• adhesive problems

Some users report excellent experiences with the G7, while others describe inconsistent reliability compared with earlier generations such as the G6.

That does not mean the stolen sensor incident reflects normal Dexcom retail stock. However, it does mean the story arrives during a period when CGM reliability, signal consistency and user trust are already under heavier discussion across the diabetes community and the wider CGM industry.

Online forums react to Dexcom warning

The announcement quickly spread across Reddit diabetes communities and online diabetes forums, where users discussed unofficial CGM sellers, emergency sensor purchases and the risks associated with secondary marketplaces.

Some users pointed out that unofficial CGM resale markets have existed for years, particularly in countries where people face high out-of-pocket costs, insurance gaps or prescription delays.

Others noted that many buyers assume sealed packaging means a product is legitimate and safe. Threads discussing second-hand Dexcom sensors and unofficial sellers have appeared online for years.

Some users on Reddit said they had previously purchased sensors from unofficial sellers during insurance gaps or while waiting for replacement supplies, often believing sealed boxes meant the products were genuine.

That creates a difficult situation because packaging can still appear authentic even when products originate outside authorised pharmacy channels.

The wider issue of unofficial CGM resale markets

Unofficial resale markets for CGM sensors have quietly existed for years, particularly in countries where diabetes technology access remains expensive or inconsistent.

Across online marketplaces and social media groups, it is not unusual to see people attempting to buy or sell:

• spare CGM sensors
• replacement transmitters
• unopened pump supplies
• expired diabetes technology
• “extra” insurance-covered stock

Some people sell surplus supplies after changing systems. Others try to help people who temporarily lose insurance coverage or struggle to afford replacement sensors.

But unofficial diabetes technology markets can carry significant risks.

Buyers may have little way of knowing whether sensors have been exposed to excessive heat, previously damaged, recalled, expired or diverted from disposal channels entirely.

The Dexcom case appears unusual because the products were allegedly diverted after being earmarked for destruction rather than standard commercial distribution. However, the incident still highlights vulnerabilities within medtech supply chains that many CGM users may never previously have considered.

Dexcom already facing wider reliability scrutiny

The timing is awkward for Dexcom because the company has already faced growing scrutiny over manufacturing quality and CGM reliability during the past two years.

In 2025, the FDA issued a warning letter connected to manufacturing and quality control concerns involving Dexcom sensors.

Separate recalls and corrections involving receivers and app alerts have also affected some Dexcom systems.

Meanwhile, diabetes forums continue to see discussion about:

• sensor failures
• false readings
• signal loss
• premature shutdowns
• missed alerts
• adhesive problems

Some users report excellent experiences with the G7, while others describe inconsistent reliability compared with earlier generations such as the G6.

That does not mean the stolen sensor incident reflects normal Dexcom retail stock. However, it does mean the story arrives during a period when CGM reliability is already under heavier discussion across the diabetes community.

How users can protect themselves

Dexcom is advising users to obtain CGM products through authorised pharmacies and approved distributors wherever possible.

Practical steps for CGM users may include:

Check lot numbers

Users concerned about affected stock should compare packaging against the lot numbers identified by Dexcom.

Be cautious with unofficial sellers

Emergency purchases happen, particularly where healthcare access or insurance systems create supply gaps, but unofficial marketplaces can carry additional risks.

Watch for unusual sensor behaviour

Potential warning signs may include:

• repeated signal loss
• failed insertions
• missing readings
• unusual skin reactions
• inaccurate glucose trends
• sensors ending early

Store sensors correctly

Even genuine sensors can be affected by excessive heat or poor storage conditions.

Keep packaging

Lot numbers and packaging details may become important if future safety notices or recalls emerge.

The bigger trust question

CGM systems are increasingly treated less like optional accessories and more like critical daily infrastructure for diabetes management.

That makes supply-chain trust, product disposal procedures and distribution security issues far more important than many users may ever previously have considered.

Most people assume diabetes devices arriving through pharmacy channels have passed every expected quality and safety process. The idea that rejected sensors could allegedly bypass disposal systems and re-enter circulation challenges that assumption.

Dexcom says it identified the affected lots through ongoing quality and accounting reviews.

For many CGM users, the story is not simply about two affected lots. It raises broader questions about how diabetes technology is distributed, monitored and protected once devices leave manufacturing facilities and enter increasingly complex global supply chains.