I’ve been considering HIFU for my saggy jowls. If it ‘melts fat’ is this a bad thing? Surely it should tone and shrink the skin? Won’t less fat under my skin make things worse as the years pass? Less plumpness to sit on?

These are all great questions and this is what I struggle with when it comes to HIFU. Focused ultrasound energy absolutely has the ability to tighten and lift the skin which is what has made these treatments popular. But to do that, the focused energy needs to be delivered very precisely onto the collagen within the skin – to heat it, damage it and prompt collagen renewal — and depending on whereabouts you’re looking in the face, that depth can vary.

If the ultrasound energy is focused into a patch of fat, it can heat, damage and melt that fat. Ultrasound is often offered as a treatment to do precisely this.

Some facial ultrasound treatments are offered with a general ‘shrinks fat and tightens skin’ promise which sounds a bit random for my liking. (Are you supposed to be happy with either? Or to get a bit of both? Maybe it’s fine if you’ve got fatty jowls and plenty to lose.)

But if you definitely want the tightening and lifting, then you need an experienced practitioner and preferably one who is using a system like Ultherapy that has an ultrasound visualiser unit, so that the practitioner can see exactly where, within the skin, each zap of energy is landing, to make sure it goes in the right place.