Firmer Skin Before the Holidays: When to Start Radiofrequency and What to Expect by Christmas
Two sessions and a result that builds over time: an honest radiofrequency calendar for the holidays, based on the date you start.
You've read that radiofrequency can burn, or hollow out the face, and you want to know what really happens. The short answer: warmth during the treatment and redness that lasts a few hours are common; a small burn is possible but rare; a hollowed face has not been measured in the studies we read.
This article ranks the effects from most common to rarest, says where each piece of data comes from, and what changes the risk.
What happens to almost everyone
Radiofrequency heats the skin in depth. During the treatment, you feel warmth. When you leave, your skin may be pink.
For XERF, the clinic sums it up this way: no downtime, back to your usual activities the same day, temporary redness is possible. When it comes, it lasts a few hours.
Why the risk sits at the surface
The heat has to reach the deep layers without harming the skin it passes through. According to the manufacturer (Cynosure Lutronic), XERF uses two frequencies (6.78 and 2 MHz), built-in cooling that protects the surface during each pulse, and a reading of the skin's resistance at every pulse to meter the energy.
These mechanisms lower the risk, they don't remove it. A radiofrequency burn happens when too much energy concentrates in one spot: the settings and the way the handpiece is moved are what prevent it.
From most common to rarest
| Effect | What the studies we read report | How long |
|---|---|---|
| Warmth during treatment | Expected, it is how the treatment works | The length of the session |
| Redness | 18 people out of 26 in a 2026 study; 5 out of 32 in a 2025 study | A few hours |
| Mild swelling | 3 people out of 26 (2026 study) | Less than 24 hours |
| Small burn | 3 out of 32 (2025 study), healed without a mark; none out of 26 (2026 study) | Variable, to be checked |
| Dark mark or change in sensation | No cases in the 2026 study, which looked for them | n/a |
These figures come from two small studies, with no control group, on devices that are not XERF. They give an order of magnitude, not a probability for you.
In the 2026 study: no burns, no dark marks, no change in sensation in 26 people. In the 2025 study: three small burns out of 32.
The hollowed face: where the reputation comes from
The idea gets around: heat would melt facial fat, and the face would look hollow. We found no study that measures it for XERF.
A 2026 study (Kim, Plastic and Reconstructive Surgery Global Open) ran the opposite test: 25 slim women, five low-energy monopolar radiofrequency sessions, and an ultrasound before and after. Cheek fat thickness increased by 1.6 mm on average at 18 weeks. Its limits are significant:
- a single author, a single centre, no control group;
- microscope analysis on only one person;
- a low-energy protocol, different from a XERF session.
So we don't cite it to say radiofrequency adds volume. It only shows that the opposite fear isn't backed by the measurements available. We draw no conclusion either way.
What changes the risk
The risk doesn't depend only on the device. What moves it:
- The energy chosen. The higher it is, the higher the heat.
- Passes over the same spot. An area heated too long concentrates the energy.
- Your skin that day. Irritated, tanned or broken skin is treated differently, or not at all.
- Your medical file. Pregnancy or an implanted electronic device, such as a pacemaker, call for an assessment before any treatment.
Here, a medical esthetician sets up XERF: the device meters the energy at every pulse, and she chooses the depth and intensity based on your skin and what you feel. A session lasts 90 min, enough time to cover the full face and neck without rushing.
When to call the clinic
Redness that fades within the day is expected. Call us if you notice:
- redness that is still there the next day;
- a small mark, a blister or an area that hurts to the touch;
- a change in how your skin feels.
We'd rather see a mark for nothing than hear about it three weeks later. We don't give home-care instructions in an article: we tell you what to do once we see you. How the session feels is covered in the article does it hurt, and the full details on the XERF page.
Questions we are asked
Can radiofrequency hollow out the face?
No study we read measures it for XERF. A small 2026 study on another radiofrequency even measured slightly thicker cheek fat after the sessions, with major limits. We can't draw a conclusion.
Can it burn?
It's possible, but rare. In a 2025 study, three people out of 32 had a small burn, which healed without a mark. Built-in cooling and the settings are there to prevent it.
How long does the redness last?
According to the clinic, a few hours, when it comes.
I have a mark the next day: what should I do?
Write or call us the same day. The team wants to see it, and will tell you what to do based on what it sees.
Are side effects more common with a home device?
We found no study comparing the two. A home device heats far less, and nobody adjusts it to your skin: their risks can't be compared with figures.
Sources
- Kim J, Sung K, Park Y, Yi KH. Facial contour modulation and skin tightening using 40.68-MHz unipolar radiofrequency. Lasers in Medical Science, 2026;41(1):163. PubMed Central
- Suh DH, Lee SJ, Song KY, Yang H, Chae SJ, Ryu HJ. Evaluation of Improvement in Skin Laxity and Oiliness After Monopolar Radiofrequency Treatment: A Pilot Study Utilizing Multiple Assessment Tools. Journal of Cosmetic Dermatology, 2025;24(10):e70463. PubMed Central
- Kim JS. Adipogenesis and Stem Cell Activation in Facial Fat After Repeated Low-energy Continuous Monopolar Radiofrequency. Plastic and Reconstructive Surgery Global Open, 2026;14(8):e7972. PubMed Central
- Cleveland Clinic. Radiofrequency (RF) Skin Tightening. my.clevelandclinic.org
- Cynosure Lutronic (manufacturer). XERF. cynosure.com/xerf
