Isn't GLP-1 creating a "feel-good" starvation? Patching the receptors telling the brain one is not hungry and then just letting the body starve happily, leading to significant muscle loss and aged face? Contrary to e.g. water fast where the body switches to 100% ketosis that can run as long as there is any fat in the body and one supplements electrolytes (Mg/K/P/HCO3) and vitamins (predominantly B1/B2/B3), leading to…
GLP1s do not themselves cause any worse muscle loss than you would experience if you lost the weight by watching calories the old fashioned way. "Ozempic face" is almost certainly an artifact of people who spent their life significantly overweight having somewhat looser skin than they would if they had maintained a low weight throughout their life. Also, not everyone gets the face effect, not by a long shot.
There are two modes the human body operates normally - insulin-driven, active when carbs are in the food, and ketone-driven, active when there is a lot of fat storage and no food intake, or food has no carbs. Insulin-driven operation switches to starvation when food intake has caloric deficit but still enough carbs for insulin to be triggered; ketones on the other hand lead to zero insulin activity and pure fat burning; starvation is only activated when humans reach around 4% body fat while in ketosis.