I used a combo of low-dose retatrutide, tesamorelin, and ipamorelin and lost about 15lb over 45 days, including 60% of my visceral fat, and put on 4lb of muscle, per before-and-after DEXA scans. I lifted regularly, ate well, and prioritized protein, and while I definitely under-ate protein, I was very pleased to find that I was able to increase muscle mass while cutting the fat. My visceral fat was the primary target here, since I'd been unable to get it to budge despite consistent training and diet. Very pleased.

You lost muscle because you lost around 1.54% of body weight per week, which is way too aggressive. The maximum recommended amount for losing weight while retaining muscle is around 1%. You will also most likely experience a weight rebound.

Hasn't this mostly been debunked? You lose muscle mass because you lost mass overall, and whether you lost it too quickly or not is not the major factor. AFAIK maintaining muscle mass while losing fat is borderline impossible for anyone who isn't extremely fat and/or very disproportionate composition to begin with.

Not at all, this is a well-known and long-established risk of rapid weight loss. Even long before any of these drugs existed, medical guidance was to lose weight slowly to help limit lean muscle loss.

Not as far as I know. The ratio of fat-to-muscle loss depends on several factors, most notably the rate of weight loss (see https://pubmed.ncbi.nlm.nih.gov/34371981/). In fact, retatrutide is popular notably because it is known to preserve lean body mass better than other weight loss drugs.

> because it is known to

I thought that this was not yet substantiated in human trials? There's a plausible mechanism and, I think a mouse trial, right?

Seems you are correct according to https://pubmed.ncbi.nlm.nih.gov/40609566/: "The proportion of lean mass loss to weight loss was similar to other obesity treatments."

You need to define how much muscle mass you expect to lose. The entire idea behind the bulk/cut cycle is that you want to net gain muscle after a full diet cycle.

It's also not borderline impossible to maintain the majority of your muscle mass, but it depends on how you eat and train. We don't know enough about the person above's diet, training, current body composition, etc. to say anything for certain.

GLP1 destroy muscle tissue.

nope

It's interesting you mention this (anhedonia), since the guardian just published this article: https://www.theguardian.com/science/2026/apr/06/is-retatruti...

How did you actually feel? Disinterested in stuff, ennui, or other?

Yeah, basically disinterested. Somewhat burnt out from doing things I normally love doing such as going on walks, programming on weekends, gaming, and work. It wasn't a really big problem, I only noticed it when looking retroactively at my experience.

How much of that is just from your hormones being trashed due to a severe deficit?

Large caloric deficits (1000+/day) in leaner people is known to tank T levels among other things. When I was on such large deficits, I had very weird mood/arousal swings. Nothing that problematic for someone with as much executive control as me but it was very weird to be held hostage to.

This is crazy. You lost 28 lbs (15% of your body weight) in 10 weeks. Why did your doctor to allow you to continue? By any common sense, that is an unhealthy pace to lose body weight.

Why?

Your internal organs can't keep up with that kind of mass fluctuation, for one. Keep an eye on your kidneys.

It seems to be more complicated (or unpredictable?) than that:

> In this study, rapid weight loss was associated with the loss of kidney function in males with normal weight, and with improvement of kidney function in overweight males.

> Our study showed that BMI and BMI change were not associated with eGFR change in females.

https://pmc.ncbi.nlm.nih.gov/articles/PMC4658128/

Those are sizable drops for 10 weeks unless you stopped lifting as well

Mentioned above, but "I worked out 6 days a week still, but swapped out 1 of my leg days for a run day (between 2-4 miles)"

Even if you hadn't lost any muscle mass, zero chance you're going to see the same exercise performance on a calorie deficit.

This is untrue. There are 100s of YouTube videos of amateur body builders preparing for a show. They are able to maintain their muscle mass while in a calorie deficit. Yes, it is insanely hard, but it can be done.

I didn't say that you can't maintain muscle mass. I'm saying your performance will suffer.

Did you work out during those 10 weeks any? TBH if you went from regular lifting to not for 10 weeks I'd expect a similar decrease in your lifting numbers (though not a .4lb/day weight loss of course)

I worked out 6 days a week still, but swapped out 1 of my leg days for a run day (between 2-4 miles)

Did you try increasing protein intake during the cut?

Dude, you must be jacked. Great lifts at those weights. Unreal bench haha. Good shit, dude.

solid bench brother

thank you:^)