Neck line treatment in Daegu — injections or radiofrequency, which comes first?
To the question “What is good for neck lines?” we first have to ask one back: what kind of neck lines? There are at least three kinds, and each suits a different treatment. And there is far less research on the neck alone than on the face.
The short answer
The order of treatment for neck lines is set by the type of line. Fine lines and rough texture from thinning skin suit dermal injections such as Rejuran or Re2O; deep horizontal creases from skin folding repeatedly suit botulinum toxin or filler-type treatment; a neck that sags because deeper layers have dropped suits radiofrequency lifting. The three are often mixed, so we separate them on examination first, and we build into expectations the fact that booster studies focused on the neck are almost non-existent.
Neck lines come in three kinds
| Type | Why it forms | Approach that fits |
|---|---|---|
| Fine lines · rough texture on thinning skin | Loss of dermal collagen, dryness | Dermal injections — Rejuran · Re2O · BYRYZN |
| Deep horizontal creases (necklace lines) | Repeated folding of the skin, neck muscle bands | Botulinum toxin or filler-type treatment; RF in some cases |
| A sagging, slack neck | Structural sagging of deeper layers | Radiofrequency lifting — not booster territory |
Neck skin is thinner than facial skin and has fewer sebaceous glands, so it dries easily and fine lines set in readily. In principle that makes it an area where injections that supply material or hold water are pointed in the right direction. But filling the dermis does not unfold a deeply folded crease.
On examination we look with the head raised and lowered, and sitting and lying down. Which lines disappear with posture and which remain tells us the type.
What injections can be expected to do on the neck
As far as we could find, there are no Re2O or Rejuran studies focused on the neck. Even the Re2O split-face trial (20 people, 20 weeks) was on the face. So the honest expectation is not “the neck lines will smooth out” but “texture becomes more even and fine lines less noticeable”.
| Class | What it does | Data confirmed for the neck |
|---|---|---|
| Rejuran (PN) | Creates an environment in which skin recovers well | No neck-specific study found |
| Re2O (hADM) | Directly supplies lost material | No neck-specific study found |
| BYRYZN (cross-linked HA) | Places a water-binding material; reversible | Considered for shallow neck lines — the study naming the product was on the face |
| Diluted CaHA | Collagen stimulation without volume | 2017 neck and décolleté biopsy study of 20 people — Korean approval covers facial wrinkles |
We state the scope of approval separately. Using CaHA on the neck and décolleté has been studied abroad, and in 2026 the US FDA approved CaHA for décolleté wrinkles, but the approved indication in Korea is the face.
What for a sagging neck and deep creases?
A neck that sags and slackens is a problem of layers deeper than the dermis, so radiofrequency lifting is the direction that fits. Density, XERF and Oligio Kiss all have tips or settings usable on the neck, but we could not find device-specific studies that evaluated the neck separately. If the skin is genuinely stretched to the point of folding, it is beyond the limits of non-surgical devices.
Deep horizontal creases are the result of repeated folding, so we first discuss filler-type treatment that works on the crease itself, or botulinum toxin that works on the neck muscle bands. Expecting boosters alone to smooth these creases is not realistic.
How to choose by neck concern
| Concern | Consider first | Why |
|---|---|---|
| Fine neck lines with dry, rough texture | Rejuran or Re2O | Supplies environment or material to thinned dermis |
| First treatment, and you want a reversible material | BYRYZN | Can be broken down with hyaluronidase |
| Deep horizontal neck creases | Discuss filler or botulinum toxin | Boosters do not unfold a crease |
| A sagging, slack neck | Discuss radiofrequency lifting | A problem of deeper layers |
| Texture of face and neck together | Plan the areas separately | Skin thickness differs by area |
Which treatment is right is decided not by the product but by which kind of neck line you have now.
Summary
What is established
- Neck lines divide into fine lines, deep horizontal creases and sagging, each suiting different treatment
- Neck skin is thinner than facial skin and has fewer sebaceous glands
- There is a neck and décolleté biopsy study of diluted CaHA (20 people) — the Korean approval covers the face
What we could not find
- Rejuran or Re2O studies focused on the neck
- Density, XERF or Oligio Kiss studies that evaluated the neck separately
- A standard number of sessions for neck lines
Neck line treatment in Daegu: frequently asked questions
For neck lines, is Rejuran or Re2O better?
No study has compared the two on the neck. For fine lines on thin, dry neck skin both are candidates; the difference is whether to address the recovery environment (Rejuran) or to put in material directly (Re2O).
Will injections make neck lines disappear completely?
No. Deeply folded horizontal creases are not unfolded by boosters. Fine lines and texture becoming less noticeable is the realistic expectation.
Does radiofrequency lifting work for neck lines?
For a neck that sags and slackens, radiofrequency is the direction that fits. We could not find device-specific studies evaluating the neck separately, though, and for fine lines or deep creases RF is not the first choice.
How many neck injection sessions do I need?
No standard number of sessions for the neck has been set by research. We review progress at least four weeks after one session and then decide on more.
Can I have Radiesse on my neck?
Abroad there are studies using diluted CaHA on the neck and décolleté, and in 2026 the FDA approved it for décolleté wrinkles, but the approved indication in Korea is the face. We explain this difference first at consultation.
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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
- Re2O split-face trial — Severance Hospital, Yonsei University; split-face, double-blind randomised trial (NCT07155278), International Journal of Molecular Sciences 2026. 20 subjects · 20 weeks · Re2O on one side, hyaluronic acid on the other. Exploratory in scale.
- CaHA dilution — 2017 neck and décolleté study, 20 subjects, dilution of 1:2, 1:4 or 1:6 assigned by skin thickness; biopsies at baseline, 4 and 7 months showed increased type I collagen. Not a study comparing dilutions with each other.
- CaHA approvals abroad — US FDA, Radiesse Summary of Safety and Effectiveness Data (P050052 and subsequent supplements). Facial wrinkles 2006 · dorsal hand 2015 · jawline contour 2022 · décolleté 2026 (152 subjects · 84-week multicentre randomised trial). Jawline and décolleté are outside the Korean approval.
- The level of PN evidence — Polynucleotides in Aesthetic Medicine: Current Practices and Perceived Effectiveness, Int J Mol Sci 2024 (evidence grade and limitations) · Expert Perspectives: Evidence-Based Applications of Polynucleotides, Clin Cosmet Investig Dermatol (that PN is not a volumiser).
- 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.