A common pattern shows up in LADA discussions again and again: someone is diagnosed with Type 2 diabetes, metformin controls their blood sugar well for a while, somewhere between a few months and a year, and then it quietly stops. Not dramatically, just a slow upward creep in home glucose readings that gets chalked up to diet slipping or stress.
It usually isn’t diet. When people in this situation compare notes in support groups, the same suggestion tends to come up: ask about LADA, a term many of them had never heard before.
Looking for the pattern instead of the excuse
Going back through weeks or months of glucose logs and diet notes side by side often reveals numbers climbing steadily regardless of what was eaten, which doesn’t match how Type 2 usually responds to diet changes. That inconsistency is the thing worth flagging, not a reason to log meals more carefully.
Bringing those logs to an appointment and asking directly for a GAD65 antibody test and a C-peptide test is often the turning point. Many doctors won’t have suggested either test on their own, not out of negligence, just because the case looked ordinary on paper: no unusual risk factors, an unremarkable first glucose test.
When the results reframe everything
A positive GAD65 result paired with a C-peptide reading lower than expected for the length of a Type 2 diagnosis points to LADA. The medication didn’t fail because of anything the person did wrong. It failed because it was treating the wrong mechanism. Metformin improves how the body uses insulin. It can’t do much if the body is steadily losing the ability to make insulin in the first place, a mechanism covered in more depth in Why Metformin Might Stop Working for You.
What usually changes next
Care doesn’t need to get more complicated, just more accurate. Once LADA is identified, C-peptide tends to get tracked periodically instead of waiting for oral medication to fail outright, and a realistic timeline for insulin can be discussed in advance instead of arriving as a surprise.
If your own numbers are drifting for no clear reason, that drift is data. It’s worth a direct question at your next appointment, a request for a GAD65 and C-peptide test specifically, rather than a resolution to try harder with diet alone.
For the mechanics of why this happens, see Why Metformin Might Stop Working for You and LADA vs. Type 2 Diabetes.