Neck fat and platysma - what would be the best treatment? (Photo)

I don't really see any neck fat on you but you do seem to have platysmal bands that could absolutely improve if you get neurotoxin such as xeomin injected. I will warn that you tend to need a high volume of neurotox as this is a wide broad muscle so it needs to be treated in a wide area.

Yes! Your injector is correct in his/her treatment plan. Relaxing these muscles will help the appearance of the skin laxity on your neck. It is a minimally uncomfortable treatment, no more painful than other areas you have received Botox in, in the past. Another treatment I would look into to further improve your results would be something like Morpheus8 micro needling. This will help by shrinking excess tissues, tightening the skin and building collagen and elastin which is what keeps skin looking plump, firm and youthful. A combination of these two treatments is typically what we do in our practice to address our patients with similar concerns to yours.