Cryolipolysis: the most widely used of these, and we found no trial against doing nothing

A 2023 trial in Germany. The authors describe it as the first prospective, controlled, investigator-blinded split-body trial of whether post-cryolipolytic heating increases efficacy.

• One session of cryolipolysis on the lower abdomen of 25 subjects
• One randomly chosen side of the treated area was then heated with a mud pack
• Over 12 weeks: photographs, fat layer thickness (ultrasound, caliper, abdominal girth), satisfaction and side effects

The results split in two directions.

On side effects — oedema, erythema and hypesthesia faded almost completely on the heated side and remained on the non-heated side.

On efficacy — the sonographic fat reduction at 12 weeks was significantly lower on the heated side.

• Heated: 9.6%
• Non-heated: 14.1%
• P = .0003

Overall satisfaction was high, at 9.2 out of 10.

What this result says, precisely.

What is established is that heating cuts the effect. Since the drop in side effects and the drop in efficacy moved together, it leaves open that the side effects are themselves entangled with the effect — which they would be if the inflammatory response is part of how the fat cells get cleared.

What is not established is the next item.

In the trial above, both sites received cryolipolysis. What was randomised was only whether they were heated afterwards.

So there is no untreated control site.

Why that matters: over 12 weeks, the fat layer on someone's lower abdomen moves without any procedure — weight, diet, season and activity all enter. And fat layer thickness measured by ultrasound also varies with how hard the probe presses.

So the 14.1% cannot be read as 'the procedure reduced fat by 14.1%'. It means the treated site was that much thinner 12 weeks later.

We found no randomised trial comparing cryolipolysis against a sham procedure or no treatment.

To be precise: this is not 'it does not work'. A trial that ran and came out negative and a trial we could not find are different things.

But across this site's procedures layer, results have differed between places that had an inert control and places that did not. On PRP the blinded raters could not tell it from saline; on IPL and deoxycholic acid the treatment beat its control. The point is that you could not have known in advance.

And this was 25 people and a single session. In practice people usually have several.

A 2023 review gathered the adverse events of cryolipolysis specifically. It searched PubMed across study designs without restriction — randomised trials, prospective cohorts, case series, case reports and reviews.

The authors' conclusion, as written:

Since its FDA approval in 2010, our understanding of the potential risks and complications associated with cryolipolysis has grown significantly, and shown that the procedure may not be as harmless as once thought.

They add that continued post-market surveillance and documentation of adverse event cases are needed to understand the true risks.

Why this sits outside the evidence-strength ladder, as 'procedure data'. It is not an efficacy claim, and it is not a clinical trial we graded ourselves. It is what the literature reports.

But the sentence gives context to the two items above. Thin evidence on the efficacy side while the risk side keeps widening is where this procedure currently stands.

The authors also note that 'cryolipolysis' and 'CoolSculpting' are often used interchangeably, which makes adverse events hard to interpret when devices and protocols differ under one name. The exosome page records a problem of the same character — when one word does not denote the same thing, results cannot be pooled.