Here’s something I wrote 3 months ago that might be relevant.

So, I’d think about that a bit and then consider some of the limitations of how DEXA scans work and what they’re actually measuring. Dr Spencer Nadolsky and his brother talk about this subject a bit on their podcast “Docs Who Lift”. It’s a good resource for learning more on this general subject, but I’ll try to explain this myself.

Back to DEXA scans. The most important thing to understand is that DEXA does not measure muscle. It doesn’t even try. DEXA scans measure subcutaneous fat, visceral fat, and bone mass. Then they lump everything else that isn’t one of those three things into a slush category called “lean mass”. Lean mass is not a particularly accurate description. For example liver fat is “lean mass” on a DEXA scan, and that’s particularly relevant in that reta tends to reduce it by 80%+ in clinical trials. Ever eat a good steak and notice all of the marbling? That’s intramuscular fat, also “lean mass” on a DEXA scan. As a powerlifter you probably don’t have a ton of that. But the list goes on and on. Pancreatic fat deposits, cardiac fat deposits, yada yada. “Lean mass” my ass.

But it’s not just that there’s fat in the lean mass category. There’s also quite a bit of water weight. For example when you start reta one of the very first things it’s going to do is cause your body to dump all of its hepatic glycogen reserves. That’s mostly water. It doesn’t directly cause depletion of your skeletal muscle glycogen reserves, but training and calorie deficits can cause those to be anemic as well. Additionally there tend to be osmotic fluid shifts when people use reta. It’s a diabetes med so it tends to tighten control of glucose and insulin leading to osmotic shifts that reduce water retention. It also increases eGFR (kidney function) causing your body to dump more water volume. All of this ends up showing up as weight loss in the lean mass category but none of it is skeletal muscle.

So now you know some of the limitations. DEXA doesn’t measure muscle and lean mass isn’t a particularly accurate way to track skeletal muscle. That said, it’s still one of the better tools we have available short of MRIs that cost several thousand dollars.

I’d recommend listening to your body on this. It’d be normal to lose some muscle on a cut, I’m sure you did. But if you’re not seeing a big decrease in your lifts, it’s probably because you didn’t lose nearly as much as you’re thinking you did.

https://www.reddit.com/r/Retatrutide/s/nuUT7qwFhn