Image courtesy of Dexcom Inc
Dexcom has warned that some G7 sensors intended for destruction after failing company quality standards were allegedly stolen and resold through unofficial supply channels.
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.
Reliability remains under the spotlight
For many CGM users, trust is built over thousands of readings, alerts and treatment decisions. Reliability is one of the most important factors when choosing a sensor, particularly for people using CGMs overnight, during exercise or as part of a hybrid-closed loop system.
Dexcom has recently highlighted trust, consistency and accuracy as key priorities as it develops future generations of CGM technology. Read more in Dexcom’s next CGM is taking shape — here’s what G8 could mean.
The timing is also notable because 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.
Improving consistency between users is one reason manufacturers are investing in new sensor algorithms and adaptive technology. Read more about adaptive sensing and future CGM accuracy improvements.
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.
Reaction from online forums
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.
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.
In the UK, CGM sensors supplied through the NHS are intended for the use of the named patient and not for resale. Many diabetes Facebook groups and forums ban the buying and selling of CGM sensors altogether, reflecting long-standing concerns about patient safety, product authenticity, storage conditions and and where supplies have come from.
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.
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
If a sensor ends before its intended wear period, our guide explains what to do when a CGM sensor fails early, some of the most common causes and what can be done to reduce the risk.
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.
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