GGT worth pulling or overkill?

GGT is cheap informational value. It catches things ALT/AST miss (biliary issues, alcohol-related changes, some medication effects). Not strictly necessary but worth the $15 once a year. In your routine 2-3x/year pulls, I'd include it in one of them.

Sold. Adding it next time.

I include GGT in every LFT panel I run. The extra number has caught something useful maybe 1 in 15 panels. Good insurance for the price.

Yeah pull it. For $15 you're getting another data point on hepatic function that actually means something different than ALT/AST. GGT specifically shows bile duct stuff and gamma-glutamyl transferase activity, so if you've got elevated transaminases you can actually figure out if it's hepatocellular damage or cholestasis. Most people running peptides should have baseline and then maybe once a year unless something flags weird. Not overkill at all.