No trial has tested RF microneedling as a treatment for submental fat. There is no randomised study, no controlled study, nothing dedicated to the question.
What does exist is one study that measured the fat layer while testing something else.
Wu and colleagues (2024) ran a split-face study of microneedle fractional radiofrequency, with and without poly-L-lactic acid, in 32 people, 30 of whom completed it. They used ultrasound to measure the submental area before and after.
The dermis thickened. The fat layer did not change significantly. The authors named the paper for that finding: the title states the treatment improves laxity "without Lipolysis".
One further study treated the lower face and submental area in 30 patients and measured volume change in three dimensions — but that was a dose-response study looking at energy settings, not an efficacy trial with a control group. It cannot answer whether fat was reduced.
Put together: the published evidence supports RF microneedling tightening the skin under the chin. It does not support it reducing the fat under the chin.
A double chin can come from loose skin, from fat, or from both. They are different problems.
RF microneedling at studied settings works on the dermis. Review chapters on non-surgical neck rejuvenation place RF-with-microneedling in the mild-to-moderate skin laxity category, and route submental fat to different modalities entirely.
That is not a criticism of the treatment. It is a mismatch between what the device does and how it is sometimes sold. If your concern is skin quality and laxity under the jaw, the treatment is aimed at the right tissue. If your concern is a fat pad, it is not.
Morpheus8's FDA clearance does not name a single cosmetic use.
"Double chin", "submental fat", "fat reduction" and "skin tightening" appear in none of them. Neither do acne scars, wrinkles, cellulite or stretch marks.
Two points to hold together. First, using it off-label is legal and routine, and doctors do this constantly across medicine. Second, a clearance would not have proved it works anyway — 510(k) clearance means a device is substantially equivalent to an earlier device, not that a benefit was demonstrated in trials.
One more caveat that applies to every Morpheus8 page: almost none of the published RF microneedling research used Morpheus8. It comes from Lutronic, Jeisys, Pollogen, Lumenis and unnamed devices. Readers searching a brand name are usually being shown evidence generated on other machines.
These are described neutrally, as different tools for a different problem. None of this is a recommendation, and each has its own trade-offs to discuss with a clinician.
Deoxycholic acid injection (Kybella). This is the outlier in regulatory terms: it is an FDA-approved drug, not a cleared device, approved in 2015. Its approved indication is "improvement in the appearance of moderate to severe convexity or fullness associated with submental fat in adults" — submental fat is literally the approved use. Its label also states plainly that use outside the submental region "has not been established and is not recommended". It works by breaking open fat cell membranes. It involves real downtime: swelling, bruising, pain, numbness and firmness after each session, commonly described as lasting one to two weeks, though that figure is clinical description rather than a number from the drug label. The labelled risks include marginal mandibular nerve injury, which causes an uneven smile, and difficulty swallowing. Usually up to six sessions, at least a month apart.
Cryolipolysis (CoolSculpting). A device that cools fat cells until they die, then the body clears them over the following weeks. Its indication is cold-assisted lipolysis — breakdown of fat — and submental and submandibular treatment is separately indicated. It is a fat device only: no cryolipolysis indication anywhere contains the words laxity, wrinkle, lift, tighten or collagen. Its characteristic complication is paradoxical adipose hyperplasia, where the treated fat pad enlarges instead of shrinking; a 2025 systematic review and meta-analysis of 28 studies and 13,078 patients estimated pooled incidence at 0.22%, about 1 in 455 patients, graded low-certainty, above the manufacturer's quoted figure of 0.025%.
Surgical options. Submental liposuction and neck lift surgery remain the direct route, and the reviews cited above route significant preplatysmal fat toward surgical and percutaneous approaches rather than dermal treatments.
A practical note that gets missed: removing fat can reveal skin laxity that the fat was concealing. That is why these treatments are often discussed as complements rather than alternatives.
Here is the tension in the marketing.
An analysis of the FDA's MAUDE postmarket database from 2013 to 2025 found 114 reports containing 224 adverse events for RF microneedling devices. Fat loss was the third most-reported category: 26 of 224 events, 11.6%.
In other words, the same capability being sold as a benefit under the chin appears in the FDA's own data as an unwanted effect elsewhere.
Two caveats must go with that number, and they matter.
The honest reading is that fat loss is real, plausible, depth- and energy-dependent, and unquantified. It is not a reason to be frightened of the treatment. It is a reason to be sceptical of it being sold as a fat-reduction procedure.
If you get cold sores, tell the clinic when you book rather than on the day. Antiviral medicine is started in advance, so it has to be arranged ahead of the appointment. There is no published cold sore data specific to radiofrequency microneedling — the precaution is carried over from laser resurfacing, where reactivation is well documented.