One thing worth mentioning: ALT and AST can transiently INCREASE in the first 2-4 weeks of GLP-1 therapy in some patients. This is thought to be related to mobilization of hepatic fat and transient hepatocyte stress as lipids are being cleared from the liver. So if anyone gets early labs that show a bump — don't panic. It's like the liver equivalent of a "healing crisis." If they're still rising at 8-12 weeks, that's when you need to investigate further. My ALT actually went from 56 to 74 at week 3, then plummeted to 31 by month 3. Classic pattern.

> ALT and AST can transiently INCREASE in the first 2-4 weeks This is accurate and well-documented. I always warn patients about this so they don't see a bump at their first follow-up and discontinue therapy out of fear. The mechanism is indeed thought to be hepatic lipid mobilization. I recommend first liver enzyme recheck at 8-12 weeks, not 2-4 weeks, precisely to avoid this confounding signal. If at 12 weeks enzymes are still elevated or rising, then we investigate — but that's rare.