Radiofrequency microneedling is a product category. Fine needles are driven to a depth the operator selects, and radiofrequency current heats the tissue around them. That much is shared. Almost everything else differs by machine: how many needles are in the tip, how far apart they sit, how deep they can go, whether the shafts are insulated, and how much energy each needle carries.
This matters when you are reading a claim about your neck. A clinic offering "RF microneedling for the jawline" is naming a category. The published results for that area were produced by two specific machines, and neither is the one most often advertised.
The larger one used non-insulated needles. A retrospective series of 98 people treated the neck and reported an average 73.3 per cent improvement in a neck ageing score at three months and 75.1 per cent at six months in the group that had three sessions, against 37.0 per cent and 41.6 per cent after a single session. It is an uncontrolled cohort, scored on a rating scale, not a randomised trial.
The smaller one used insulated needles. A prospective pilot in 33 people used a fractional high-intensity focused radiofrequency device on the lower face and neck. The angle under the chin, measured photographically, improved by 28.5 degrees at six months, and a second chin angle by 16.6 degrees. Tissue samples from the same work showed the zone of heat damage confined to the dermis, with the outer layer of skin spared. Downtime was reported as three to four days.
Neither cohort used Morpheus8. That is not a criticism of the device. It is a statement about where the numbers came from, and it is worth knowing before a figure from one of these papers is quoted to you under a different brand name.
Insulated needles are coated along the shaft with only the tip exposed, so the energy is released at depth. Non-insulated needles conduct along the entire shaft, including where the needle crosses the skin surface, so the surface takes a thermal injury at every entry point.
The mechanical logic is sound and widely accepted. But there is no published head-to-head trial comparing the two designs, in any skin type, so it is not a settled ranking. Non-insulated devices have produced good results in practice: a 44-person study using non-insulated tips in Fitzpatrick skin types III to V reported pigment change in 2 of 40 people.
What the difference does mean is that the two neck cohorts are not interchangeable evidence. One tells you what a surface-heating design did to a rating scale. The other tells you what a dermis-confined design did to a measured angle.
Energy per needle is the second setting worth asking about. A 2025 study combining pig-skin histology with 30 patients found a near-linear relationship between energy per needle, across 20 to 100 mJ, and the volume of coagulated tissue - a correlation of 0.976. Two of that paper's four authors were affiliated with a device manufacturer. Regulators have tied the same variable to skin type: above 62 mJ per pin, the Morpheus8 applicator is limited on-label to Fitzpatrick skin types I to IV.
There is no dedicated trial of radiofrequency microneedling for submental fat. The claim is common in marketing and absent from the literature.
The one study that measured the fat layer directly - a split-face study with 30 people completing, using ultrasound on the submental area - found dermal thickness increased and the fat layer unchanged. Its title is built around exactly that: improved laxity without lipolysis, lipolysis meaning the breakdown of fat.
Fat loss does appear in this literature, but from the other direction. An analysis of the FDA's MAUDE postmarket database, January 2013 to October 2025, found 114 reports containing 224 events for radiofrequency microneedling, of which 26 were fat loss. MAUDE is voluntary reporting with no denominator, so that is a proportion of the reports filed and can never be turned into a chance that something happens to you. It establishes that unwanted fat loss is a real reported phenomenon, not an incidence.
If what is under your chin is a fat pad, the treatments whose authorised wording names submental fat are deoxycholic acid injection and cryolipolysis. Review chapters on non-surgical neck rejuvenation route fat in front of the platysma muscle to those, and place radiofrequency with microneedling in the mild-to-moderate skin laxity group.
Four questions do most of the work.
Six months is the evidence horizon for this whole class. No properly measured study runs longer. Clinic copy saying results last one to three years has no published source.
If you get cold sores, say so when you book - not on the day. Antiviral medicine is started in advance, so it has to be prescribed before the appointment. There is no published data on cold sore reactivation after radiofrequency microneedling specifically; the precaution is carried over from laser resurfacing, where reactivation is well documented and prophylaxis is standard.
Also mention a pacemaker or an implantable defibrillator, and any metal implant near the treatment area. These are labelled contraindications for radiofrequency devices, and they are precautionary rather than tested - no published study has treated patients with cardiac implants. The right people to advise you are your cardiology team, not a clinic.
Say if you have a history of keloid or thickened scarring, an active infection or active inflamed acne in the area, or a skin cancer treated there.