Is ultherapy worth it for my double chin? (Photos)

You don't really have much of a double chin on the photos, so Without an exam, it will not be possible to fully evaluate you and give you recommendations.   If there's fat left to the touch, then Kybella would help.  We love Ultherapy and in my experience patients do well with is as a MAINTENANCE tool, so you could certainly consider it, but one needs to be realistic and Without an exam, it will not be possible to fully evaluate you and give you recommendations. 

Congratulations on your weight loss! From your pictures I do not see a significant amount of submental tissue (double chin). I would recommend you to have a  consultation with a board certified practitioner in your area. Our practice offered Kybella, CoolSculpting, & Ultherapy and an in person consult is always essential to recommending the best treatment for each patient. If the double chin contains fat then I'd recommend Kybella since it appears to be a very small area. If the area is simply loose skin then I would recommend Ultherapy. Ultherapy will not remove fat-it lifts & tightens. We frequently use Ultherapy AFTER CoolSculpting or Kybella destroys the fat. 

There really is no right or wrong answer to your question.  You can definitely get some tightening benefit of your jawline with botox called the Nefertiti neck lift but this will require maintenance treatment.  Ultherapy can also be helpful with longer-lasting benefits.  In my opinion, mixed reviews occur with Ultherapy due to variable techniques and technicians.  To avoid this variability, I recommend that you consult with a board-certified and experienced cosmetic physician.