EVIDENCE
Research evidence — studies by treatment, with the doctor's comments
At ReYeonK Clinic we look at the research when recommending a treatment. For each treatment we list selected studies—mainly meta-analyses and randomized trials—with links to the original on PubMed, and Dr. Lee Doochan adds how he applies them in practice. Studies on safety and side effects are included together with how we prevent them.
Ultherapy
Ultherapy →- High · meta-analysis / randomizedMeta-analysis · 42 studies
Microfocused Ultrasound With Visualization (MFU-V) Effectiveness and Safety: A Systematic Review and Meta-Analysis.
Amiri et al. · Aesthet Surg J 2025 · PMID 39540440
This review pooled 42 studies of microfocused ultrasound with visualization (MFU-V). Improvements in lifting and skin texture were reported in both physician and patient assessments. Average pain was 4.9 out of 10 (moderate), and redness, swelling and bruising were mostly mild and passed on their own. Results vary by individual.
Doctor's comment — Dr. Lee Doochan
Ultherapy is one of the most extensively studied lifting devices. Because pain is moderate, we explain it before treatment, apply numbing cream, and use sedation when needed.
- High · meta-analysis / randomizedMeta-analysis · 17 studies · 477 people
Systematic review and meta-analysis of safety and efficacy of high-intensity focused ultrasound (HIFU) for face and neck rejuvenation.
Ayatollahi et al. · Lasers Med Sci 2020 · PMID 32026164
Across 17 studies of HIFU for the face and neck, the treatment was safe in the short term with a moderate degree of improvement. No hyperpigmentation was reported. However, studies used different assessment methods and long-term follow-up was limited.
Doctor's comment — Dr. Lee Doochan
Results of HIFU vary greatly depending on who designs the treatment—which layer, how many shots and how. When it is placed precisely for where the sagging is, some patients see a clear change without surgery. Results vary by individual.
- High · meta-analysis / randomizedSafetySystematic review · 19 papers · 506 people + 106 FDA reports
Microfocused Ultrasound With Visualization: A Systematic Review of Adverse Events and Risk of Subsequent Facelift Compromise.
Humphrey et al. · Dermatol Surg 2025 · PMID 39625163
In published studies, temporary swelling, redness and pain were most common, and serious adverse events were rare (one case of subcutaneous atrophy). The FDA reporting database included reports of fat loss, nerve symptoms and scarring, but most were unverified. The claim that Ultherapy makes a later facelift harder is not yet supported by evidence.
Doctor's comment — Dr. Lee Doochan
For patients with little facial fat, we adjust depth and shot count so that less heat reaches the fat layer.
Thermage FLX
Thermage FLX →- High · meta-analysis / randomizedRandomized split-face trial · 20 people
A Randomized, Split-Face, Evaluator-Blind Clinical Trial Comparing Monopolar Radiofrequency Versus Microfocused Ultrasound With Visualization for Lifting and Tightening of the Face and Upper Neck.
Alhaddad et al. · Dermatol Surg 2019 · PMID 30531187
One side of the face was treated with monopolar radiofrequency (Thermage-type) and the other with MFU-V (Ultherapy-type) on the same day, then compared for 6 months. Both sides improved from day 30 and stayed improved through day 180, with no statistical difference between the devices. Side effects were also similar.
Doctor's comment — Dr. Lee Doochan
Thermage and Ultherapy are not so much better or worse as acting on different layers. Which one suits you—or whether to combine them (Ulthermage)—is decided in consultation based on skin thickness and degree of sagging.
- High · meta-analysis / randomizedRandomized trial · 20 people
A Randomized Evaluator-Blinded Trial Comparing Subsurface Monopolar Radiofrequency With Microfocused Ultrasound for Lifting and Tightening of the Neck.
Jones et al. · Dermatol Surg 2017 · PMID 28902019
A randomized comparison of a single session of either device for neck laxity. Both reduced laxity from day 90 through day 180, with no difference in effect. Procedural pain was greater with MFU-V, and side effects were mild and temporary in both groups.
Doctor's comment — Dr. Lee Doochan
This study found no difference between the two devices. In practice, we suggest Thermage first when neck skin firmness is the concern, and Ultherapy when a double chin bothers you. Results often build up from around three months. Results vary by individual.
- Moderate · clinical / comparativeSafetyMulticenter clinical study · 86 people
Multicenter study of noninvasive radiofrequency for periorbital tissue tightening.
Fitzpatrick et al. · Lasers Surg Med 2003 · PMID 14571447
A multicenter study of a single Thermage treatment around the eyes, followed for 6 months, observed improvement in periorbital wrinkles and changes in brow position. Second-degree burns occurred in 21 of 5,858 applications (0.36%), and 3 people had small residual scars. It studied a first-generation device, earlier than today's FLX.
Doctor's comment — Dr. Lee Doochan
Thermage has more than 20 years of research behind it. Burns were reported occasionally in early studies; today we use FLX, with improved cooling and energy control.
ONDA
ONDA →- Moderate · clinical / comparativeRetrospective comparison · 171 people (Korea)
Efficacy and Safety of Microwave Energy-Based Device for Facial Rejuvenation: A Retrospective Comparative Study With High-Intensity Focused Ultrasound.
Nam et al. · Aesthet Surg J 2026 · PMID 41403025
This study compared facial treatment with a microwave device (89 people) and HIFU (82 people). The microwave group changed faster at one month with less pain (2.3 vs 4.7) and fewer side effects, while HIFU gave longer-lasting lifting and firmness at three months. Both were safe, and the authors concluded that they play different roles.
Doctor's comment — Dr. Lee Doochan
Onda works on the fat layer, and Ultherapy on the deeper SMAS layer. So we suggest Onda for those with fuller faces who worry about pain, and Ultherapy when sagging is the main concern.
- Moderate · clinical / comparativeClinical trial · 53 people (no control group)
Effects of microwave technology on the subcutaneous abdominal fat and anthropometric indices of overweight adults: A clinical trial.
Pahlavani et al. · J Cosmet Dermatol 2022 · PMID 34021953
Fifty-three overweight adults received three microwave treatments to the abdomen 20 days apart and were measured up to day 60. Abdominal fat thickness and waist circumference decreased compared with before treatment. Without a control group, the results are hard to generalize.
Doctor's comment — Dr. Lee Doochan
Body Onda shows contour changes more clearly when you have already lost some weight.
- Reference · expert recommendationsInternational expert recommendations
Microwave-Energy-Based Device for the Treatment of Cellulite and Localized Adiposity: Recommendations of the "Onda Coolwaves" International Advisory Board.
Hoffmann et al. · Bioengineering (Basel) 2024 · PMID 39768067
Experienced users of Onda Coolwaves from several countries summarized recommended settings, patient selection and treatment methods for cellulite and localized fat. The authors note that long-term efficacy and safety have not yet been fully evaluated.
Doctor's comment — Dr. Lee Doochan
Evidence is still building for newer devices, so we treat with settings aligned to the international recommendations.
Skin Booster
Skin Booster →- High · meta-analysis / randomizedSystematic review · 9 studies · 219 people
The Effectiveness of Polynucleotides in Esthetic Medicine: A Systematic Review.
Lampridou et al. · J Cosmet Dermatol 2025 · PMID 39645667
Across nine studies of polynucleotide (PN, the ingredient in Rejuran) injections, several reported improvements in wrinkles, skin texture and elasticity, and side effects were mostly mild and temporary. However, study quality was low to moderate and injection sites and methods varied, so there is not yet consensus on the best way to use it.
Doctor's comment — Dr. Lee Doochan
With skin boosters, the response to the first session matters. If one session brought no change, repeating it is unlikely to help, so we discuss other options. We choose the ingredient according to your skin. Results vary by individual.
- High · meta-analysis / randomizedRandomized split-face trial · 27 people
Comparison of the effects of polynucleotide and hyaluronic acid fillers on periocular rejuvenation: a randomized, double-blind, split-face trial.
Lee et al. · J Dermatolog Treat 2022 · PMID 32248707
One eye area received PN and the other non-crosslinked hyaluronic acid, three injections two weeks apart. Overall improvement scores were similar, while gains in elasticity, hydration, texture and pores were larger on the PN side. There were no serious side effects.
Doctor's comment — Dr. Lee Doochan
For thin skin such as around the eyes, we think first of PN, which strengthens the skin itself, rather than adding volume.
- High · meta-analysis / randomizedRandomized controlled trial · 162 people · multicenter
Efficacy and Safety of Poly-L-Lactic Acid Microspheres for Temporal Hollowing Correction: A Multicenter, Randomized, No-Treatment-Controlled, Evaluator-Blinded Trial.
Ting et al. · Aesthetic Plast Surg 2026 · PMID 42983071
A multicenter randomized study compared PLLA microsphere injections for temple hollowing with no treatment. The treated group showed clear improvement at 6 months that was maintained to 12 months. Treatment-related side effects occurred in 8.5%, with no serious events.
Doctor's comment — Dr. Lee Doochan
Unlike fillers that add volume right away, Sculptra builds up over several months, so it suits people who want a natural change.
Filler
Filler →- High · meta-analysis / randomizedSafetySystematic review · 48 randomized trials
Adverse Events Associated with Hyaluronic Acid Filler Injection for Non-surgical Facial Aesthetics: A Systematic Review of High Level of Evidence Studies.
Kyriazidis et al. · Aesthetic Plast Surg 2024 · PMID 37563436
Using only 48 randomized trials, this review classified adverse events of hyaluronic acid (HA) fillers. Most were brief injection-site reactions that resolved on their own; serious events were rare but can occur and needed active treatment. The authors concluded that thorough explanation, informed consent and practitioner training are essential.
Doctor's comment — Dr. Lee Doochan
Fillers are a relatively safe procedure, but I believe being ready to respond immediately to rare complications matters more. That is why we always keep an emergency kit and hyaluronidase (the dissolving injection) on hand.
- High · meta-analysis / randomizedSafetyMeta-analysis · 21 studies · 231 people
Hyaluronidase Protocol in Management of Hyaluronic Acid Filler-Related Vascular Complications: A Systematic Review and Meta-Analysis.
Alhusain et al. · Aesthetic Plast Surg 2026 · PMID 41249530
This analysis looked at hyaluronidase (the dissolving injection) in cases where a blood vessel was blocked after HA filler, causing skin necrosis or vision problems. Outcomes were better the sooner it was used—within 6 hours—and skin necrosis recovered better with adequate doses. The conclusion: such events are rare, but a rapid response is key.
Doctor's comment — Dr. Lee Doochan
One reason we use HA fillers is that they can be dissolved if a problem arises. We ask patients to contact us right away if they notice pain or a change in skin color after treatment.
- High · meta-analysis / randomizedMeta-analysis · 5 randomized trials · 748 people
Efficacy and Safety of Hyaluronic Acid Fillers for Midface Augmentation: A Systematic Review and Meta-Analysis.
Safia et al. · Medicina (Kaunas) 2025 · PMID 41155810
Pooling randomized trials of HA filler for midface volume, the filler groups responded better than controls, with no increase in moderate-to-severe side effects. However, differences compared with other fillers were not notable. The authors concluded that consultation to set realistic expectations is important.
Doctor's comment — Dr. Lee Doochan
This study found little difference between products, but each filler has different physical properties (firmness, spread), so choosing the right product for each area matters too. Together with where and how much is injected, it shapes the result—and our principle is not to overfill.
Summaries are ReYeonK's own plain-language summaries of the published abstracts. Study results apply to the study participants; individual results vary. ·
