Something that comes up a lot with GLP-1 plus metformin, and the part people forget: the 12-week mark isn't a finish line for fasting numbers. Typical picture is A1c dropping nicely (7.9 to 6.8 is a real move), weight down maybe 14 lbs, post-meal numbers looking way better — and then fasting glucose just sitting there at 135-150 most mornings, which is confusing as hell when everything else is improving.
Common surprise: on a CGM it's fairly flat overnight until about 4 am, then it climbs. That pattern is usually the dawn phenomenon — liver dumping glucose as cortisol and other counter-regulatory hormones come up — rather than the medication failing. Post-meal control improving first makes sense, because that's largely about slowed gastric emptying, incretin effect and less glucose hitting the bloodstream at once. Fasting is a different animal: it's mostly about baseline hepatic insulin sensitivity and how much glycogen the liver is willing to release overnight. That tends to move later, and it often tracks more with weight loss and visceral fat coming down than with the drug itself. People commonly report fasting being the last number to budge, sometimes well past week 12.
Worth knowing before you compare options or timelines: fasting is also the number most affected by sleep, stress, late meals, and how long the gap is between dinner and the morning reading. So the honest answer to "does GLP-1 just take longer for fasting?" is kind of both — the drug helps, but the fasting drop usually shows up once enough weight and liver fat come off, and for a lot of people that's later than the A1c improvement. Anyone seen fasting finally break below that range after week 12, or did it only move as the weight kept coming down?
