Somewhat tangent - I've lost about 20% on semaglutide. What I discovered, since I lost quite a lot of muscles as well, my lower back pain, related to crack in one vertebrae, got really bad. Once I reached my weight goal (just a hair above "normal" weight, coincidentally where I plateaued), I started weights lifting, starting at very low numbers, and keeping semaglutide at about half dosage. It seems to help so far.
Just something to consider for someone who need to lose a lot of weight and who has some underlying condition. It is still worth it in my opinion, just not as painless as one could think.
So a bit late but this is definitely a thing, but as far as I know, with any kind of rapid weight loss, the loss of muscle "lean mass" can be an issue.
Did your doctor warn you by any chance about the cracked vertebrae and the interplay with losing weight/muscle? I'm assuming not but that is definitely not the kind of pre-existing condition that someone might notice (though I'd hope a doctor could notice/forsee that)
Starting to pair lifting weights with the treatment seems to be what everyone is suggesting is figuring out now, much like you did[0]. Along with that, probably some remodeling of eating habits is required (instead of just eating less).
Just something to consider for someone who need to lose a lot of weight and who has some underlying condition. It is still worth it in my opinion, just not as painless as one could think.