How long do Density and XERF last? — how to decide when to retreat
“How many months will it last?” is the question we hear most. Online, “six months to a year” is a common answer, but no human data have followed Density or XERF for that long. This column separates what has been measured from what is simply custom.
The short answer
How long Density and XERF last cannot be answered from device data. Human follow-up ended at 24 weeks for Density and at 90 days at most for XERF. For RF lifting in general, device-measured elasticity was significant from 4 weeks and clinical assessment at 12 weeks; some studies put the peak at four to six months and one reported a slight decline at seven to ten months, but most of these used older devices and none had a control group. So Miso Clinic decides Density or XERF retreatment from the state of the face after the two-to-three-month assessment, not from a calendar, and sets no fixed “so many times a year”.
How many months have Density and XERF results been measured for?
| Device | Study | Last measurement |
|---|---|---|
| Density (Jeisys Medical) | Oku 2025 · 16 people | 24 weeks |
| XERF (Lutronic) | Hwang 2025 · 20 people | 12 weeks |
| XERF (Lutronic) | Weiss 2026 · 39 people | 90 days |
| XERF (Lutronic) | Erlich 2026 · 16 people | 3 months |
What happens after 24 weeks for Density and after 90 days for XERF has never been measured for either device. When you see “lasts a year”, it is more accurate to ask which device, how many people and whether there was a control group.
When do RF lifting results such as Density and XERF appear, and when do they fade?
- Right afterTight feelingImmediate collagen contraction and swelling — it settles soon and is not counted as a result.
- 4 weeksDevice-measured elasticityIn a study of 20 Korean women, device-measured elasticity was significant from 4 weeks, but clinical assessment was not yet significant.
- 12 weeksClinical assessment significantIn the same study, jawline and nasolabial fold improvement became significant at 12 weeks and held to 24 weeks.
- 4–6 monthsPeak (older-device studies)Two independent studies reported the peak at four to six months.
- 7–10 monthsSlight decline (one study)Data after this point are thinner still.
This RF lifting timeline comes from monopolar RF studies that did not use Density or XERF and had no control groups. We do not turn it into a duration for Density or XERF.
Is the feeling that Density or XERF has “worn off” accurate?
The same result at the same time point looks different depending on who assesses it. In a review of 16 ultrasound lifting studies, practitioners judged 92% improved at 90 days but patients judged 42%. In the other direction, in a one-year study (20 people) blinded observers rated only 43% improved while patient satisfaction was 95–100%, and quantified lift peaked at 90 days and fell to 22–33% at one year.
So the feeling that Density or XERF has “worn off”, or that it is “still there”, can both differ from measurement. That is why Miso Clinic takes photos under fixed conditions before treatment and retakes them under the same conditions for comparison.
How is the timing of Density or XERF retreatment decided?
| Situation | Decision |
|---|---|
| Less than 2–3 months since Density or XERF | Postpone the decision — change is still under way |
| Sagging remains at the 2–3 month assessment | Plan the same device or a different one |
| Density or XERF change feels maintained | No rush — the pace of ageing differs between people |
| Recent strong heat treatment on the same area | Wait until recovered |
| Lost volume has newly become prominent | Consider a volume treatment instead of a device |
Recommendations to repeat Density or XERF “every six months” or “twice a year” are custom, not the result of comparative studies. The 2026 study cited to argue that starting early pays off in the long run was computer modelling with no actual people.
Density and XERF duration summary — what is established and what is not
What is established
- Density follow-up 24 weeks, XERF follow-up 90 days at most
- RF in general: device measurement 4 weeks · clinical assessment 12 weeks · peak reported at 4–6 months (no control groups)
- Improvement rates at the same time point differ greatly by rater (92% vs 42%)
What we could not find
- Six-month or one-year duration data for Density or XERF
- Studies comparing Density or XERF retreatment intervals
- Human data showing regular treatment is better in the long run
How long Density and XERF last: frequently asked questions
How many months do Density results last?
Human Density data were followed for only 24 weeks, so there are no data on what happens after that. The four-to-six-month peak reported for RF in general does not come from Density data.
How many months do XERF results last?
The longest follow-up in human XERF data is 90 days. How long XERF lasts beyond that has never been measured, so we do not promise a number of months.
How many times a year should I have Density or XERF?
No study has compared Density or XERF retreatment intervals, so there is no set number. Miso Clinic decides the next session from the state of the face after the assessment two to three months after treatment.
It feels like the effect has gone. Can I have it again straight away?
If it is less than two to three months since Density or XERF, change may still be under way, so we postpone the decision. Comparing photos taken under the same conditions sometimes shows that the feeling and the reality differ.
Can starting early slow ageing?
The 2026 study cited to argue for starting Density or XERF early was computer modelling with no actual people, and all groups converged by year 15. We could not find human data confirming the claim.
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Who wrote this
Written and reviewed by Lee Chi-Hak, MD, medical director of Miso Clinic in Daegu, South Korea. Every study cited above is given together with its design, its size and the limitations the authors themselves recorded, and where we could not find data, we have said that we could not find any.
| Medical director | Lee Chi-Hak, MD |
|---|---|
| Address | 4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, South Korea · Exit 1, Kyungpook National University Hospital Station |
| Phone | +82-53-428-2700 |
| Hours | Weekdays 11:00–19:00 (lunch 13:00–14:00) / Saturday 10:00–16:00 (no lunch break) / Closed Sundays and public holidays |
| Columns | All clinical columns |
| Reference library | All booster and device references |
References
- Density human study — Oku K, J Cosmet Dermatol 2025;24(10):e70504, PMID 41090512. 16 adults · one session · 24 weeks · no control group. 3D imaging tightening distance 0.82 ± 0.36 mm; pain 1.4 ± 0.6 (5-point scale).
- Three XERF human studies — Hwang JK, Medical Lasers 2025;14(1):23–30 (20 subjects · one session · 12 weeks) · Weiss RA et al., Cureus 2026;18(3):e104546, PMID 41930066 (39 subjects · two sessions · 90 days, manufacturer support) · Erlich G et al., Lasers Med Sci 2026;41(1), PMID 42611100 (retrospective, 16 subjects · one session · 3 months). None of the three has a control group.
- Timeline of RF results — Cosmetics 2024;11(3):71 (20 Korean women: clinical assessment not significant at 4 weeks · significant at 12 and 24 weeks; device-measured elasticity from 4 weeks) · Weiss 2026 (84.6% at 30 days → 92.3% at 90 days) · Fitzpatrick 2003 and Edwards AF et al., Dermatol Surg 2013;39:104–110 (peak at 4–6 months). None has a control group.
- Improvement rates that depend on the rater — review of 16 ultrasound lifting studies (IJERPH 2023;20(2):1522): at 90 days, practitioners 92% vs patients 42%. Werschler 2016 (20 subjects): at one year, blinded assessment 43% vs patient satisfaction 95–100%; quantified lift was greatest at 90 days and fell to 22–33% at one year.
- Miso Clinic clinical protocols — criteria for indications, design by area, and the explanation and consent process before treatment. The source of the sentences marked “clinical judgement” in this column.
Everything in this column is general information and does not replace medical diagnosis or treatment. Effects and side effects vary with individual skin condition, age and underlying illness, and the same result is not guaranteed for everyone. Any decision to proceed should be made in an in-person consultation with a physician.