Ultherapy is cleared for use on the face, neck and décolletage . It currently is not FDA approved for use on the body.
Ulthera can be used on many areas of the body where you want to build collagen support. This can include the buttocks, arms, knees, thighs, abdomen, etc. although this would be considered off label, it works in the same way as it does on the face - it builds collagen and hence tightens the region being treated.