Fat loss after Ultherapy or Thermage is rare. Here is where the cases come from
About 1 in 500.
That is how often fat loss shows up in the published studies on Ultherapy, going by a 2025 review that pulled together 19 papers and 506 patients.
In the FDA complaint database, fat loss is one of the things reported most often.
Both numbers are real. The truth sits somewhere between them.
A reader on our post about treatment order asked about this. They said they couldn't risk losing the little facial fat they had left, and it deserved a longer answer than a reply.
We run Ultherapy, Thermage and Xerf ourselves, so read this knowing we are not neutral.
What the papers say
Studies are small, and they are mostly run by people who are very practised with the device. The complaint database is the opposite.
Anyone can file, nothing gets checked, and nobody knows how many treatments sit behind each report.
A group of doctors who published 5 serious cases in 2018 wrote that these problems are probably underreported. So it's rare, and it is probably a bit less rare than the papers make it look.
Radiofrequency shows the same pattern. An older review from a clinic in Madrid followed 290 patients treated with the same type of RF that Thermage uses.
Fat atrophy was on their list of less common side effects. The authors linked their problems to overheating and recommended moderate energy with no overlapping passes.
Where it comes from
Heat is meant to land in one specific layer. Fat loss is what you get when too much of it lands in fat instead.
Nobody has studied the cause cleanly, so what follows is how it works in practice. Two things matter most.
How deep the device goes over areas that are already lean, and how much energy ends up in one spot.
This is also where the person holding the device matters, which we said we'd come back to on our shot count post.
Two people can deliver the same 300 shots. One adjusts the depth area by area and goes lighter where there is little fat to spare.
The other runs the same pattern on every face. The quote looks identical.
If your face is already lean
This is the group the question is really about. Before anything starts, ask which depth goes over your lean areas and whether any area gets left out.
A clear, specific answer is a good sign. If you get the same plan as everyone else, ask again. Ultherapy gives you an extra question.
The device shows the layers under your skin on a screen, so ask whether they looked at it over the thin spots.
There is one more group who should speak up before the device starts, and that is anyone who might want a facelift one day.
That conversation goes differently. The evidence there is thinner than either side admits.