Does XERF hurt?
For many people it is a moderate heat, and the honest word is comfortable, not nothing. Two small 2026 studies of XERF, both involving its maker, report about the same average pain score. In a prospective study of 39 people treated without any numbing, pain was generally mild to moderate with an average of 4.2 out of 10. In a retrospective review of 16 women, the average was about 4.3, with 6 women scoring mild, 8 moderate and 2 severe, one at 7 and one at 8.
Two cautions go with those numbers. In both studies the energy was set to what each person could tolerate, so the scores reflect the settings as much as the device. And both are early, uncontrolled reports. This clinic's published account puts Dr Ong's own treatment at around 3 out of 10, one person's experience and not a rule. The answer that fits the evidence is that most people find it tolerable, some find it harder, and it should not be described as sensation-free.
How do the cooling and the two frequencies relate to comfort?
XERF delivers 6.78 MHz and then 2 MHz within a single pulse, with cryogen gas cooling at the tip that can be set to one of three levels. The authors of the 39-person study state that skin cooling aids pain prevention, and the device stops its output if the tip surface passes 43 degrees Celsius. The 16-woman study held the cooling at level 1 of the 1 to 3 range of the device and tuned the energy to mild to moderate discomfort.
The two frequencies are a different matter. The authors of the 2026 study propose that delivering the energy in a fractionated pulse train with cooling may lower peak heating at the surface and so the response of the pain nerves. That is a hypothesis, offered in a discussion and not tested against another device in either paper. It is a reasonable design idea and not a proven comfort advantage.
What happens in a first session, step by step?
It starts before the device. XERF is assessed first, because it suits early to moderate laxity and not volume loss or advanced sagging; the evidence review and the XERF treatment page explain who it is for. Dr Ong performs XERF here. The steps below follow the clinic's published description and the protocol in the larger study, and the exact order in the room is his to decide.
First the skin is cleaned and the area is mapped. A thin film of gel is applied so the handpiece can move smoothly and spread the cooling evenly. The handpiece is then passed over the area in an even grid, gliding over broad areas and stamping on contoured or bony ones, with cooling running at the surface and the device reading the tissue pulse by pulse. That is why one part of the face can feel different from another in the same pass. The 39-person study recorded between 300 and 677 shots per treatment across the face and neck, which gives a sense of the number of pulses, not of how long a session takes.
You are asked how it feels, and the setting is adjusted. In the studies the energy was titrated to tolerance, and in older work on a related device, using the patient's own feedback on heat to choose the energy was found to be a valid way to set it. Afterwards the skin is flushed and warm, as set out in after XERF: downtime, aftercare and what is normal. The standard course is two sessions, four to six weeks apart.
Is numbing cream needed?
Usually not here, because the integrated cooling makes the session comfortable for most people, though comfortable is not the same as feeling nothing. The studies give a guide: none was used in the 39-person study, and in the 16-woman study a lidocaine and prilocaine cream was applied on request by 4 women, 30 minutes before. A cream is a medicine with limits on how much is safe, which the article on numbing creams explains. At The Retreat Clinic extra pain control is not usually needed for XERF. If you are anxious about pain, say so at the assessment, where the options are decided.
How does it compare with other radiofrequency devices?
Only as far as the studies allow, and they do not allow much. The live comparison, Thermage, XERF and other monopolar radiofrequency devices, found no trial that compares XERF with Thermage. Reported Thermage scores are higher in the studies read: 7.12 on the left and 6.62 on the right in a 2026 study of 46 people given the Thermage FLX, and 6.06 in a recalled survey of 64 patients, against about 4 for XERF.
Those figures use different scales, settings, numbing, people and moments of scoring, so they are not like for like. Technique also matters a great deal: in a survey of 5,700 radiofrequency treatments by 14 physicians, 45% of patients found the original high-energy single pass too painful and 5% found a lower-energy multiple-pass method too painful. This clinic runs XERF and does not offer Thermage, mainly on comfort. That is a choice about comfort and not a claim that any device gives a better or worse result, which the evidence does not support. The XERF side effects page covers what can happen afterwards, and does XERF work is Dr Ong's own account of the treatment.
