I do not need or use GLP-1 medicine, but lots of people do. It works mainly by reducing appetite and food intake, but does other useful things too.
I am a semi-fan of Creatine. Theory is that this stuff (found naturally in red meat and sold as something for muscle-building support) enhances ATP production in muscle so that muscle can be stressed more effectively.
It might be placebo effect, but I use it. I am not a body-builder.
The point is that Creatine (with exertion of course) may help reduce the muscle loss that accompanies all weight loss. If so, good.