The sensor changes every fourteen days. In my data every change leaves a gap — and afterwards a phase where I trust the readings less than usual.
What the data show
From my own sensor export.
What the data show
In the first half of 2026 I find several gaps between 80 and 200 minutes. The shortest lasted about ninety minutes, the longest three and a half hours. During that time the sensor delivers nothing — the curve breaks off and resumes later.
One gap stands out: 35 hours in April. That was not the change itself but the fact that I simply had not applied a new one.
The hours afterwards
The manufacturer states a warm-up period. What comes after that is the more interesting phase for me: the first readings often look lower or less settled than what I was used to from the previous sensor.
I have not cross-checked this — that would need a finger-prick comparison, which I do not do routinely. It remains an impression, not a finding.
That interstitial glucose lags behind blood glucose is documented. That freshly applied sensors can deviate more in the first hours is too. How large the effect is in an individual case depends on placement, tissue and fluid balance.
How I handle it
On change day I pay less attention to individual numbers. If a reading looks unusual I wait half an hour and look again rather than reacting immediately.
For the weekly picture it makes no difference. A two-hour gap every fourteen days does not measurably change a monthly average.
Anyone relying on sensor readings to dose medication should test blood in case of doubt. This page describes the approach of someone taking no medication — a different starting point.
Key points
- Every change leaves a gap of 80 to 200 minutes.
- Readings shortly after a change often look less settled.
- I have not cross-checked this — it remains an impression.
- For weekly and monthly figures the gap does not matter.
Single observation, not a study.
Sources
This entry is based on my own sensor readings. Where studies are mentioned, they are linked in the text. Continuous glucose monitoring: FreeStyle Libre 3.