Great question. The sequence of aesthetic treatments are important since multi-modality treatments are a norm these days. Because of HA filler injections used, I generally wait for 3-4 weeks later, before proceeding with HIFU treatment.
Although there is no clinical studies, however this recommendation is backed by consensus from experienced doctors who are key opinion leaders in Aesthetic Medicine.
My preference is to be safe and steady, to yield the best results for my patients and minimize any potential side effects/ complications.
Hope this helps.
Dr David Deng