How many months between XERF treatments? — Separating what research says from clinical judgement
“How many months apart should I have XERF?” More people are searching for a ‘XERF interval’ these days. To say it clearly first: no retreatment interval for XERF has been set by research. This article sets out how many sessions the studies actually used, when results settle, and how Miso Clinic decides the next point in time against that gap — keeping evidence and clinical judgement apart.
The short answer
No XERF interval (retreatment interval) has been set by research; the next point in time is a clinical judgement made by looking again at the face once the result has settled. The XERF human studies used one session (Hwang 2025 · Erlich 2026) or two (Weiss 2026), none compared intervals or numbers of sessions, and follow-up goes to about 3 months at most (12 weeks · 90 days). In radiofrequency research, clinical assessment was not significant at 4 weeks but was at 12 weeks, so deciding the next session before then means judging a change that is still in progress. Miso Clinic (4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, South Korea; +82-53-428-2700) decides whether and how to treat next after 3 months, when the result has settled, using photos taken under the same conditions and examination (clinical judgement).
How many months apart should XERF be?
There is no set number of months. To state an interval you need two kinds of data: how long the effect lasts, and a comparison of whether results differ when the interval differs. XERF has neither yet.
| Question | Confirmed by research | Not confirmed |
|---|---|---|
| How many sessions | Studies with 1 session (20 people · 16 people) · 2 sessions (39 people) | Data on people with 3 or more sessions |
| How long followed | Up to about 3 months (12 weeks · 90 days) | Data at 6 months · 1 year |
| Interval | — | Studies comparing intervals or numbers of sessions |
| When results show | In radiofrequency research, clinical assessment significant at 12 weeks (no control group) | A peak time specific to XERF |
So sentences that state flatly “XERF every 6 months” or “once a year” do not come from research.
How many times did the XERF studies actually treat people?
| Study | Subjects | Sessions | Last assessment | Design |
|---|---|---|---|---|
| Hwang 2025 | 20 women (aged 28–63) | 1 | 12 weeks | No control group |
| Weiss 2026 | 39 people | 2 | 90 days | Manufacturer supported, no control group |
| Erlich 2026 | 16 people | 1 | 3 months | Retrospective, no control group |
There is one study with two sessions, but it did not divide people into one-session and two-session groups within the same study for comparison. So “two sessions are better than one” or “a course of so many sessions is needed” cannot be said from XERF data either. The figures from the studies are set out separately in How long do XERF results last?.
When do results settle?
The timeline below comes mostly from studies of monopolar radiofrequency other than XERF, and none has a control group. Still, it can be used to set “when it makes sense to judge”.
- ImmediatelyTight feelingImmediate collagen contraction and swelling. It settles within a few days, so we do not treat it as the result.
- 4 weeksDevice measurements firstDevice-measured elasticity was significant from 4 weeks, but clinical assessment was not yet significant (20 Korean women).
- 12 weeksVisible changeClinical assessment of the jawline · nasolabial folds became significant at 12 weeks and held to 24 weeks. The XERF studies’ follow-up also reaches about this point (12 weeks · 90 days).
- 4–6 monthsPeak with older devicesData on older devices reported the peak in this period. The XERF data do not go this far.
In the 39-person XERF study (manufacturer supported), the improvement rate seen by the treating physicians also rose from 84.6% at 30 days to 92.3% at 90 days. This fits the pattern of results building up over several weeks.
Where does “every 6 months” come from?
It is not a figure from XERF research. Older studies of monopolar radiofrequency in general put the peak at 4–6 months, and with custom added on top, it seems to have hardened into a set phrase. As far as we have checked, there is no trial comparing XERF retreatment intervals of 3 months and 6 months.
Rather than “wrong”, it is a statement from a different source. For some people 6 months later is right, and for others there is no reason to hurry even after a year. Duration discussed together with Density is in How long Density and XERF results last.
How does Miso Clinic decide the next point in time?
We decide by looking at the face, not the calendar. Below are Miso Clinic’s criteria; they do not come from studies comparing intervals (clinical judgement).
| Situation | Decision |
|---|---|
| Less than 3 months since treatment | We hold off on deciding. The change is still in progress. |
| After 3 months, sagging remains | We redesign tips · areas with XERF, or consider another device. |
| After 3 months, the change seems to be holding | We do not hurry. The pace of ageing differs from person to person. |
| Volume loss stands out more than sagging | We do not repeat the same device; we switch to an approach that addresses volume. |
| Recent strong heat treatment on the same area | We wait until recovery. |
We judge by placing photos side by side, taken with the same lighting · angle · expression as before treatment. There are data in which, at the same time point, ratings split widely by rater — 92% improvement as seen by the practitioner and 42% as seen by the patient (analysis of 16 ultrasound lifting studies) — so deciding by feel alone can make it too early or too late.
How does a planned split differ from retreatment?
At the consultation, the question “When do I come back?” mixes two things (clinical judgement).
- A planned split — when the area to cover is large and it was decided from the start to split it into two sessions, or when the first session’s output was set conservatively with the plan to continue after seeing the response. This is one schedule.
- Retreatment — when, after the first design is finished and the result has been seen, a new decision is made to treat again because sagging remains. In this case we look at the face again after 3 months and decide.
The two-session study (Weiss 2026) was also designed as two sessions from the start. Keeping the two apart reduces confusion such as “Why did you ask me to come straight back this time, when last time you told me to wait?”
Does having it often, or a lot, make it last longer?
There are no confirmed data in humans. There is no XERF study comparing groups with more sessions or shorter intervals, and no study randomly assigning shot counts.
On the other hand, there are cautions about overlapping heat treatments at short intervals. Data on older devices reported blistering · burns (second-degree burns in 21 of 5,858 treatments, 0.36%) and fat atrophy (about 4 per 10,000 treatments) (Fitzpatrick 2003 · Narins 2006). These are figures from the era of the high-energy single-pass technique, not current incidences, but with no evidence that “more · more often” is a gain, there is no reason to add risk. Precautions are in XERF side effects and precautions, and the full map of XERF is in XERF lifting in Daegu: which skin it suits.
XERF interval: frequently asked questions
How many months apart should XERF be?
No interval has been set by research. The XERF studies used one or two sessions, and none compared intervals. Miso Clinic looks at the face again after 3 months, when the result has settled, and decides. This is clinical judgement.
How many XERF sessions are needed for an effect?
The XERF studies used one session (20 and 16 people) or two (39 people) and did not compare numbers of sessions. So there is no evidence for saying a course of so many sessions is needed.
How long does the effect of XERF last?
The longest follow-up in XERF human data is about 3 months (12 weeks, 90 days). Beyond that it has not been measured, and not being measured does not mean the effect has gone.
The effect seems to have faded. Can I have it again straight away?
If less than 3 months have passed since treatment, it is better to wait. In radiofrequency research, clinical assessment was not significant at 4 weeks and was significant at 12 weeks.
Does having XERF often make it last longer?
There are no confirmed data in humans. Overlapping heat treatments at short intervals can add risks such as burns and fat atrophy, so we do not hurry.
Where can I have a XERF interval consultation in Daegu?
Miso Clinic is at 4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, in front of Exit 1 of Kyungpook National University Hospital Station. +82-53-428-2700. Weekdays 11:00–19:00, Saturdays 10:00–16:00 (no lunch break); closed Sundays and public holidays.
Read next
Product pages
Related: XERF product information
Who wrote this
Written and reviewed by Lee Chi-Hak, MD, director of Miso Clinic, Daegu. The treatment standards and injection design set out here are the ones we use in practice.
| 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
- Three XERF human studies — Hwang JK, Medical Lasers 2025;14(1):23–30 (20 people · one session · 12 weeks) · Weiss RA et al., Cureus 2026;18(3):e104546, PMID 41930066 (39 people · two sessions · 90 days, manufacturer supported) · Erlich G et al., Lasers Med Sci 2026;41(1), PMID 42611100 (retrospective, 16 people · 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 — analysis 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.
- Timing and frequency of RF adverse reactions (older device) — Fitzpatrick R et al., Lasers Surg Med 2003;33:232–242 (86 subjects): blistering 2.3% immediately · 3.8% within 72 hours; second-degree burns in 21 of 5,858 treatments (0.36%) — figures for the 2002 high-energy single-pass technique, not a current incidence.
- Fat atrophy — Narins RS et al., Dermatol Surg 2006;32:115–124. Appears at 1–4 months (mean 2 months), about 4 per 10,000 treatments. Notes that heavy anaesthesia blocks pain feedback.
- XERF specifications — Lutronic published data: monopolar, 6.78 MHz plus 2 MHz, handpieces i05 (5×10 mm · 400 shots) · i10 (10×10 mm · 300 shots) · E40 (20×20 mm · 600 shots) · E60 (20×30 mm · 600 shots). In Korea it is approved in the general-purpose electrosurgical unit class; its advertising pre-screening mark is “General-purpose electrosurgical unit combination-2024-16-054”.
- Evidence for comparing radiofrequency devices — Aesthetic Surgery Journal Open Forum 2026 systematic analysis of the literature (15 studies · 1,230 people, one randomised controlled trial). It states that no direct device-to-device comparison was identified.
- Medical advertising law — Medical Service Act of Korea, Article 56(2), which prohibits testimonial advertising, comparison with other clinics, superlative claims and advertising that guarantees or implies a guaranteed treatment effect.
- Miso Clinic practice guidance — indication criteria, site-by-site design, and the explanation and consent procedure. This is the source for every sentence marked as clinical judgement.
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.
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