Retatrutide Raising Your Liver Enzymes? Why You Need a GGT Test

Why Your Liver Enzymes Look Bad on a Standard Blood Panel

If you go to your doctor and you see these elevated liver enzymes and you don't tell them you're on RETA, he's going to freak out.

And that reaction makes sense from his side of the desk, because on a standard panel the only two liver markers most doctors order are AST and ALT, and when those come back high the first thing a physician thinks about is alcohol, fatty liver, or hepatitis. He is not thinking about a guy who deadlifted heavy three days ago and is running a peptide he did not disclose.

So before you panic about a number on a page, understand what those two enzymes actually are.

AST and ALT are enzymes that live inside cells, and when a cell gets damaged or stressed, it leaks them into your blood, with ALT sitting mostly in liver tissue while AST spreads across the liver, the skeletal muscle, and the heart.

That second part is the whole reason this gets misread.

Now, one thing to note, right, is if you're actively in the gym, you're training really hard, you're going to see those numbers elevated. When you put a muscle under enough mechanical tension to grow it, you also cause enough microdamage for those enzymes to spill out into circulation, and the lab has no way to tell whether that AST came from your liver or your quads. Blood markers used to track training load are routinely elevated in athletes because of muscle turnover, not organ disease, which is exactly why sports medicine treats athlete reference ranges differently than sedentary ones (Banfi 2012).

Supplements pile another layer onto this problem, since there is a documented case of exercise-induced rhabdomyolysis in someone stacking creatine, beta-alanine, citrulline malate, and beta-ecdysterone, and rhabdo dumps enzymes into the blood on a scale that makes a training bump look small (Chowaniec 2026).

If you're on RETA Truetide, if you don't know the glucagon agonist Truetide is going to significantly increase those numbers as well. I want to be straight with you here: I have never seen a study land on that. This is what I see on client labs, not something the literature has answered, so treat it as a pattern I watch for rather than a proven effect.

To be honest with you, like the AST and ALT are just screening labs anyway, right? Like what are your liver enzymes? When they're elevated, it's not, you need to stop drinking. You need to make lifestyle changes and get further testing. An elevated screening lab is a signal to look closer, not a diagnosis.

Think of AST and ALT like the check engine light in your truck. It tells you something in the system is talking. It does not tell you whether it is the transmission or a loose gas cap, and nobody sells the engine because the light came on.

That's why we run a GGT. So this is going to give us your true liver health, and this is a better indicator, especially for people who are using supplements, active in the gym or even on gear, of course, GGT is on there.

GGT is gamma-glutamyl transferase, an enzyme that sits in the bile ducts and on the surface of liver cells, and it barely exists in skeletal muscle. So a hard training session does not move it the way it moves AST. Again, my confidence that GGT is the better read for lifters comes from watching panels over years, not from a trial that compared the two markers in trained men on peptides.

That's something that you should absolutely be monitoring. Get a GGT drawn alongside your AST and ALT, get it before you start anything, and get it again eight to twelve weeks in so you have your own baseline instead of a population average.

Research: Banfi G, Colombini A, Lombardi G et al. published their review on metabolic markers used in sports medicine through Adv Clin Chem back in 2012, and Chowaniec P, Miedziaszczyk M, Kucia M et al. documented a case of exercise-induced rhabdomyolysis tied to supplement stacking in Cureus in 2026.

References:

Banfi G, Colombini A, Lombardi G et al.. Metabolic markers in sports medicine. Adv Clin Chem. 2012. https://pubmed.ncbi.nlm.nih.gov/22397027/

Chowaniec P, Miedziaszczyk M, Kucia M et al.. Exercise-Induced Rhabdomyolysis With Supplements (Creatine, β-Alanine, Citrulline Malate, and β-Ecdysterone). Cureus. 2026. https://pubmed.ncbi.nlm.nih.gov/41952948/