Stelo Biosensor Accuracy and Calibration Information
We know accuracy has been a concern for many Stelo users, and we want to be upfront about what you should expect from your biosensor.
The technical specs
Stelo reports that it is 93% accurate compared to laboratory blood glucose tests. This means 93% of readings fall within 20% of lab values (or within 20 mg/dL for readings below 70).
Learn more from Stelo: How accurate is Stelo?
What we’re hearing from you
Since launching with Stelo, we’ve heard from members who see:
- Readings that don’t match finger sticks
- Unexpected highs or lows
- Biosensors that seem off for days at a time
We take this feedback seriously and share it with the Stelo team.
Why readings might vary
Interstitial fluid vs. blood
Stelo measures glucose in the fluid between your cells, not directly in your blood. You will often see a 10 to 15 minute lag, especially when glucose changes quickly, like right after eating.
Learn more from Stelo: Why doesn’t my Stelo match my blood glucose meter?
Calibration period
Expect the most variation in the first 24 to 48 hours as the biosensor settles in. Give it two full days before you judge accuracy.
Focus on trends, not one-off numbers
Even with some variance, Stelo can still show useful patterns, including:
- Which meals spike your glucose
- How foods compare to each other
- Overnight glucose stability
- How exercise and sleep affect your glucose
A biosensor reading of 140 vs. a finger stick of 120 isn’t ideal. Still, you can often learn that one meal spikes you more than another, or that a morning walk helps flatten your curve.
Can I calibrate Stelo?
No. Stelo is factory-calibrated and does not support manual calibration. Many members who used devices that allowed calibration find this frustrating.
We share this feedback with the Stelo team and continue to push for improvements.
What we’re doing about it
We actively share the accuracy concerns you report with the Stelo team. Send examples and context to support@levels.com.
When to flag accuracy with our team
Some variation is normal. Contact support if:
- Finger sticks consistently differ by 30+ mg/dL
- The biosensor fails in the first 48 hours
- You see patterns that do not match how you feel
We can help troubleshoot and direct you to Stelo for a replacement when appropriate.
Bottom line
Stelo isn’t perfect, and we won’t pretend it is. For many people, it still provides useful metabolic insights. Focus on patterns over precision, and reach out if something seems off.