Clinical Effects and Safety of Radiofrequency Microneedling for the Management of Melasma: A Retrospective Study

Abstract

Background

Melasma is a chronic hyperpigmentary disorder that is difficult to treat in patients with Fitzpatrick phototypes III to VI because of the risk of postinflammatory hyperpigmentation. Radiofrequency microneedling (RFMN) is an emerging modality that targets dermal photoaging while minimizing epidermal injury.

Objectives

The aim of this study was to evaluate the clinical effectiveness and safety of POTENZA RFMN in patients with melasma in a real-world retrospective cohort.

Methods

The authors conducted a retrospective pre–post observational study of adults with clinically diagnosed melasma treated with POTENZA (Jeisys Medical Inc., Seoul, Republic of Korea) at a tertiary dermatology center in Seoul, Republic of Korea, between May 2022 and May 2025. All treatments were delivered in bipolar mode at 1 MHz with an insulated microneedle tip (I-25 or I-49). The primary outcome was the change in modified Melasma Area and Severity Index (mMASI) from baseline to posttreatment. Secondary outcomes included physician-rated improvement, patient satisfaction, changes in texture and brightness, and adverse events. Sensitivity analyses were performed to assess the robustness of the findings after excluding patients who received concurrent topical depigmenting agents.

Results

Fifty patients (mean age 40.7 years; 60% female; Fitzpatrick type III in 80%) were included. Median (interquartile range) mMASI decreased from 6.15 (4.90-8.62) to 3.75 (2.18-5.92) (median ΔmMASI −1.80; median percentage reduction 32.3%; P < .001). A responder analysis using a ≥30% mMASI reduction threshold identified 27/50 patients (54%) as responders. No significant differences in ΔmMASI were observed by melasma pattern or Fitzpatrick phototype; however, male patients showed greater median improvement than female patients (−2.70 vs −1.65; P = .039). In the sunscreen-only subgroup (n = 31, functional monotherapy), the median percentage mMASI reduction was 42.3%, consistent with the overall cohort. Independent reviewers rated clinical improvement in 98% of patients (36% marked, 36% moderate, and 26% slight), and 90% of patients reported satisfaction. Procedure-related adverse events occurred in 12% of cases; all were mild, transient, and resolved without intervention.

Conclusions

POTENZA RFMN produced clinically meaningful mMASI reductions, high physician-rated improvement, high patient satisfaction, and a favorable safety profile in this predominantly Fitzpatrick type III cohort of patients with mild-to-moderate melasma. These findings support RFMN as a promising adjunctive option and warrant confirmation in prospective controlled trials.

Level of Evidence: 4 (Risk)

Melasma is a chronic acquired hyperpigmentation disorder characterized by symmetrical brown to gray-brown macules and patches predominantly affecting sun-exposed facial areas.¹ It arises from a complex interplay of genetic predisposition, ultraviolet radiation exposure, hormonal influences, and vascular factors, with recent evidence highlighting a central role for dermal photoaging, including solar elastosis, increased vascularity, and senescent fibroblast accumulation.^2,3

Melasma is classified by distribution into centrofacial, malar, and mandibular patterns and by Wood's lamp examination into epidermal, dermal, or mixed forms.⁴ Objective severity is commonly assessed using the modified Melasma Area and Severity Index (mMASI) and provides improved practicality while maintaining strong correlation with imaging-based pigmentation metrics.^5,6 Treatment selection is further influenced by Fitzpatrick skin phototype, with Phototypes III and IV exhibiting both the highest global melasma burden and increased susceptibility to postinflammatory hyperpigmentation, which poses additional challenges when using energy-based devices.^7,8

Melasma shows variable global prevalence, ranging from 0.18% in the general United States population to as high as 41% in high-risk Asian populations, with a marked female predominance.^9-11 In East Asian populations, it is one of the most common pigmentary disorders and is frequently associated with sun exposure, hormonal factors, and inflammatory features.^10-13

Current management emphasizes a multimodal approach centered on photoprotection combined with topical depigmenting agents such as tranexamic acid, thiamidol, and triple-combination therapies.^14,15 Combination regimens generally yield superior outcomes compared with monotherapies and energy-based devices, including lasers and RFMN, have emerged as effective adjunctive modalities.¹⁶ Optimal treatment should target both epidermal pigment and dermal alterations.¹⁷

POTENZA (Jeisys Medical Inc., Seoul, Republic of Korea) is an FDA-cleared RFMN platform that delivers bipolar or monopolar radiofrequency energy through insulated, semi-insulated, or noninsulated microneedles to adjustable depths (0.5-4.0 mm), producing controlled thermal coagulation zones in the dermis while minimizing epidermal injury. The device operates at 1 or 2 MHz frequencies and features multiple tip configurations, including the pumping tip for enhanced topical delivery.

Evidence from recent systematic reviews supports radiofrequency microneedling (RFMN) as an effective and well-tolerated modality for facial rejuvenation, with consistent improvements in skin quality and a favorable safety profile, consistent with its biologic rationale for pigmentary disorders driven in part by dermal photoaging.¹⁸ Another systematic review and qualitative evidence synthesis of RFMN for melasma concluded that RFMN is a promising and generally safe modality, with consistent improvements in MASI/mMASI scores across heterogeneous clinical studies, particularly in patients with darker phototypes.¹⁹

For melasma, POTENZA is proposed to act on dermal pathology by promoting collagen remodeling, reducing neovascularization, and facilitating transepidermal elimination of melanin.²⁰ Preliminary studies have reported that bipolar pulsed RFMN is safe and effectively improves melasma when used as monotherapy or in combination with topical agents.^20-22 Real-world evidence from a retrospective cohort of Japanese patients treated with POTENZA RFMN further supports this, demonstrating clinically meaningful improvements in a subset of patients and a favorable safety profile, with all adverse events (AEs) consisting of mild, transient erythema.²³ The technology's ability to customize parameters based on Fitzpatrick skin type, combined with a lower risk of postinflammatory hyperpigmentation compared with traditional lasers, positions it as a promising option for managing refractory melasma in darker skin types.

Despite this emerging evidence, comprehensive real-world data on the clinical effectiveness and safety profile of POTENZA RFMN specifically for melasma remain limited. The present retrospective study aims to describe the clinical effects and safety of POTENZA RFMN in a real-world cohort of patients with melasma treated at a single tertiary dermatology center.

METHODS

Study Design and Population

This retrospective, pre–post observational study evaluated the clinical effectiveness and safety of POTENZA RFMN for the management of melasma. Medical records of patients treated at a single dermatology center (Hallym University Kangnam Sacred Heart Hospital Dermatology Center) in Seoul, Republic of Korea, between May 2022 and May 2025 were reviewed after IRB approval (approval number 2025-07-018); informed consent was waived because of the retrospective design.

Eligible participants were adults (≥18 years) with clinically diagnosed melasma treated with POTENZA RFMN in bipolar mode, with or without topical adjunctive therapy, and with adequate baseline and posttreatment documentation, including clinical records and standardized photographs. Exclusion criteria were concomitant treatment with other energy-based devices during the study period, incomplete documentation of baseline or follow-up data, and any contraindication to RFMN.

Intervention

All treatments were performed by a single board-certified dermatologist using the POTENZA RFMN system (Jeisys Medical Inc.) in bipolar mode at 1 MHz, with an insulated 25- or 49-pin microneedle tip (I-25 or I-49; Figure 1). Treatment parameters were selected according to a predefined internal algorithm based on Fitzpatrick skin phototype and lesion characteristics:

Figure 1.

(A) POTENZA RFMN device, (B) insulated I-25, (C) I-49 tips, (D) pumping tip CP-25, (E) noninsulated N-49, and (F) semi-insulated S-25.

• Fitzpatrick type III patients received Energy level 1 or 2 at depths of 1.5 to 2.5 mm, targeting the superficial-to-mid dermis.

• Fitzpatrick type IV patients received Energy level 1 at depths of 1.0 to 2.0 mm to minimize the risk of postinflammatory hyperpigmentation.

• For predominantly malar-pattern lesions, shallower depths (1.0-2.0 mm) were used to preferentially target epidermal–dermal junction pigmentation, whereas deeper settings (2.0-2.5 mm) were used for mixed-pattern lesions to address dermal pigment and concomitant photoaging.

Pulse duration and delivery mode (single-pass, nonoverlapping) were kept constant across sessions. Patients received a median of 3 sessions (interquartile range [IQR] 1-3.75; range, 1-23) at ∼28-day intervals (IQR 28-28 days). No dermal boosters (poly-L-lactic acid or hyaluronic acid) were used in this cohort.

Concurrent topical regimens during the POTENZA RFMN treatment period were categorized as follows: sunscreen only (n = 31, 62.0%); hydroquinone-based topical depigmenting therapy plus sunscreen (n = 8, 16.0%); other nondepigmenting topical adjuncts plus sunscreen (n = 10, 20.0%); and no topical therapy, including no sunscreen (n = 1, 2.0%). In all patients using topical regimens, the regimens had been initiated at least 4 weeks before the first POTENZA RFMN session and were qualitatively stable throughout the treatment and follow-up period, although exact dosages and application frequencies were not consistently documented. All patients received standardized photoprotection counseling. A short procedure illustrating the technique is provided in Video.

Outcome Measures

The primary outcome was the change in mMASI from baseline to posttreatment. The mMASI evaluates 4 facial regions (forehead, right malar, left malar, and chin), scoring area involvement (0-6) and darkness (0-4), with total scores ranging from 0 to 24. Secondary outcomes included physician-graded clinical improvement (marked/moderate/slight/none), patient satisfaction, skin texture improvements (smoothness, brightness, and pore refinement), pigmentation lightening, and AE incidence and resolution.

Data Collection and Assessment

Data were extracted from electronic medical records using standardized forms capturing demographics, Fitzpatrick phototype, melasma distribution pattern, disease duration, treatment parameters, mMASI scores, clinical improvement grades, satisfaction scores, and AEs. Standardized photographs were obtained at baseline and at the last available follow-up visit (minimum 3 months, median 6 months post-final treatment; IQR 3-9 months) using consistent lighting, distance, and camera settings. Two independent blinded reviewers evaluated photograph pairs for clinical improvement assessment. The representative clinical cases shown in Figures 2 and 3 were selected from patients with at least 6 months of posttreatment follow-up.

Figure 2.

Reduction of melasma area. F (42). Six months follow-up. (A) Pretreatment right side. (B) After 4 sessions of POTENZA RFMN monotherapy on the right cheek. (C) Pretreatment, left cheek. (D) After 4 sessions of POTENZA RFMN monotherapy on the left cheek.

Figure 3.

Reduction of melasma area. F (45). Six months follow-up. (A) Pretreatment, right side. (B) After 5 sessions of POTENZA RFMN monotherapy on the right cheek. (C) Pretreatment, left cheek. (D) After 5 sessions of POTENZA RFMN monotherapy on the left cheek.

Statistical Analysis

Continuous variables were summarized as mean ± standard deviation or median and IQR, depending on normality testing. Categorical variables were described as absolute and relative frequencies. Changes in mMASI between baseline and posttreatment were analyzed using the Wilcoxon signed-rank test. Subgroup comparisons of absolute and relative mMASI changes according to sex, Fitzpatrick phototype, and melasma pattern were performed using Mann–Whitney U tests. Associations between categorical variables, including patient satisfaction, physician-rated improvement, and AE occurrence, were evaluated using Fisher's exact test.

Sensitivity analyses were performed (1) excluding patients using concurrent topical depigmenting agents and (2) restricting the cohort to the 31 patients receiving sunscreen only during the POTENZA RFMN period (functional monotherapy subgroup). The percentage improvement in mMASI was calculated for each patient as (baseline − posttreatment)/baseline × 100. Patients were classified into 4 predefined clinical response categories based on this percentage reduction: poor (0%-25%), fair (26%-50%), good (51%-75%), and excellent (>75%), consistent with grading systems previously reported in the melasma literature.^24-26 Additionally, patients were classified as responders or nonresponders based on ≥30% improvement in their mMASI. All tests were 2-tailed, and P-values <.05 were considered statistically significant. Statistical analyses were performed using R version 4.2.

RESULTS

Patient Characteristics

A total of 50 patients with clinically diagnosed melasma were included. The mean age was 40.7 ± 17.5 years; 30 patients (60.0%) were female and 20 (40.0%) were male. Most participants had Fitzpatrick skin type III (80.0%) and a malar distribution pattern (82.0%); mean disease duration was 51.2 ± 39.8 months. A history of pregnancy was reported by 40% of female patients. Information regarding hormonal disorders (86.0%), genetic predisposition (98.0%), and photoexposure (96.0%) was unavailable for the majority of records (Table 1).

Table 1.

Clinical and Demographic Variables

Variable	Category	n	Value
Age (years)	Mean ± SD	—	40.7 ± 17.5
Sex	Female	30	60%
	Male	20	40%
Fitzpatrick skin type	III	40	80%
	IV	10	20%
Time with melasma (months)	Mean ± SD	—	51.2 ± 39.8
Hormonal disorder	Yes	2	4%
	No	5	10%
	Unknown	43	86%
History of pregnancy (only women)	Yes	12	40%
	No	4	13.3%
	Unknown	14	46.7%
Melasma during pregnancy (only women)	Yes	3	10%
	No	4	13.3%
	Unknown	23	76.7%
Genetic predisposition	No	1	2%
	Unknown	49	98%
Photoexposure	No	2	4%
	Unknown	48	96%
Melasma pattern	Malar	41	82%
	Mixed	9	18%
Baseline mMASI score	Median (IQR)	—	6.15 (4.90-8.62)
Posttreatment mMASI score	Median (IQR)	—	3.75 (2.18-5.92)
Pigmentation intensity	Moderate	20	40%
	Mild	17	34%
	Severe	13	26%
Skin tone homogeneity	Homogeneous	39	78%
	Slight mismatch	11	22%

Unknown: documented in the medical record.

IQR, interquartile range; mMASI, modified Melasma Area and Severity Index; SD, standard deviation.

Treatment Characteristics

All 50 patients received POTENZA RFMN in bipolar mode at 1 MHz with an insulated microneedle tip. The RF energy level was categorized as low (Level 1) in 24 patients (48.0%) and as medium (Level 2) in 26 patients (52.0%). Depth settings ranged from 1.0 to 2.5 mm. The mean number of treatment sessions was 3.24 ± 3.51, with a median of 3 (IQR 1-3.75; range, 1-23): 17 patients (34.0%) received 1 session, 5 (10.0%) received 2, 15 (30.0%) received 3, 4 (8.0%) received 4, and 9 (18.0%) received 5 or more sessions. No dermal boosters were used (Table 2).

Table 2.

Treatment Parameters, Clinical Improvement, and Safety

Variable	Category	n	Value
RF Mode	Applied	50	100%
Cartridge Type	Applied	50	100%
Topical adjunct use	None	1	2%
	Hydroquinone	8	16%
	Sunscreen only	31	62%
	Other	10	20%
Sessions (n)	Median (IQR)	—	3 (1-3.75)
Session interval (days)	Median (IQR)	—	28 (28-28)
Skin smoothness improvement	Yes	44	88%
	No	6	12%
Skin brightness improvement	Yes	42	84%
	No	8	16%
Pigmentation improvement	Median (IQR)	—	2 (1-2.75)
Patient satisfaction	Yes	45	90%
	No	5	10%
AEs	Yes	6	12%
	No	44	88%
AE resolved	Yes	6	100%
Concomitant medications	Yes	31	62%
	No	19	38%
Medication class	Anti-inflammatories	18	36%
	Skin lighteners	14	28%
	Photoprotectors	13	26%
	Other	13	26%
Medication format	Oral	5	10%
	Both (oral + topical)	26	52%
	NA	19	38%
Indication for medications	Acne	16	32%
	Skin lightening	14	28%
	Photoprotection	13	26%
	Other	15	30%
Clinical improvement	Median (IQR)	—	2 (1-3)

AE, adverse events; IQR, interquartile range; NA, not applicable; RF, radiofrequency.

Concurrent topical therapy during the RFMN period was distributed as follows: sunscreen only (n = 31, 62.0%), hydroquinone-based topical depigmenting agent plus sunscreen (n = 8, 16.0%), other nondepigmenting topical adjuncts plus sunscreen (n = 10, 20.0%), and no topical therapy, including no sunscreen (n = 1, 2.0%).

Objective Improvement in Pigmentation (mMASI)

Baseline and posttreatment mMASI scores were 6.15 (IQR 4.90-8.62) and 3.75 (IQR 2.18-5.92), respectively (Figure 4). The Wilcoxon signed-rank test showed a significant reduction in mMASI after treatment (P < .001), indicating a marked clinical improvement in melasma severity following POTENZA RFMN treatment.

Figure 4.

Boxplot (full cohort), showing modified Melasma Area and Severity Index (mMASI) scores at pretreatment and posttreatment for the full cohort, with individual patient data points overlaid.

At baseline, the mean mMASI was 7.03 ± 3.28 (median 6.15; IQR 4.90-8.62; range, 1.2-15.4), which decreased to 4.64 ± 3.26 (median 3.75; IQR 2.18-5.92; range, 0.6-14.7) posttreatment (Table 3). The mean absolute change in mMASI was −2.38 ± 1.86 points, with a median reduction of −1.80 (IQR −3.00 to −1.20). All patients showed stable or improved mMASI scores, with no worsening.

Table 3.

Primary Outcome—Change in mMASI

Time	Value	P-value
Baseline mMASI score	6.15 (4.9-8.6)	.001*
Posttreatment mMASI score	3.75 (2.18-5.92)

mMASI, modified Melasma Area and Severity Index.

^*P < .001.

Expressed as a percentage, the mean reduction in mMASI was 36.3 ± 23.4%, with a median reduction of 32.3% (IQR 14.4%-55.9%; range, 0%-78.9%). Using the predefined thresholds, 31 patients (62.0%) achieved ≥25% reduction, 27 (54.0%) achieved ≥30% reduction, and 18 (36.0%) achieved ≥50% reduction.

In a responder analysis using a ≥30% reduction threshold, 27 of 50 patients (54.0%) were classified as responders and 23 (46.0%) as nonresponders. When categorized by predefined clinical response groups, 19 patients (38.0%) had poor (0%-25%), 13 (26.0%) had fair (26%-50%), 17 (34.0%) had good (51%-75%), and 1 (2.0%) had excellent (>75%) improvement.

Physician-Assessed Clinical Outcomes

Physician-rated overall clinical improvement on a 4-point ordinal scale (0 = none, 1 = slight, 2 = moderate, 3 = marked) was rated as none in 1 patient (2.0%), slight in 13 (26.0%), moderate in 18 (36.0%), and marked in 18 (36.0%). Thus, 36 of 50 patients (72.0%) achieved moderate or strong clinical improvement.

For overall skin appearance (0-3 scale), 1 patient (2.0%) was rated as no improvement, 9 (18.0%) as mild, 23 (46.0%) as moderate, and 17 (34.0%) as strong improvement; 40 patients (80.0%) achieved at least moderate improvement. Improvement in skin smoothness was recorded in 44 patients (88.0%), improvement in brightness in 42 (84.0%), and improvement in pigmentation in 45 (90.0%).

Patient-Reported Outcomes

Patient satisfaction was documented in 45 of 50 patients (90.0%); 5 (10.0%) reported dissatisfaction (Figure 5). The patient-reported global outcome (0-3 scale) was distributed as: no effect in 5 patients (10.0%), mild in 31 (62.0%), moderate in 7 (14.0%), and significant in 7 (14.0%); overall, 45 patients (90.0%) perceived at least some benefit, and 14 (28.0%) reported moderate or strong improvement. Narrative descriptions consistently noted smoother and more even skin texture.

Figure 5.

Bar graphs showing patient satisfaction with POTENZA RFMN treatment.

Safety

Treatment-related AEs were documented in 6 patients (12.0%); 44 patients (88.0%) had no reported AEs. The observed AEs included transient erythema, scaling, isolated mild erythema, and transient swelling. All AEs were graded as mild and fully resolved within 1 week, either spontaneously or with simple supportive care. No moderate or severe AEs, persistent pigmentary alterations, scarring, or infections were observed.

Subgroup and Exploratory Analyses

Changes in mMASI (Δ = post–pre) by subgroup are summarized in Table 4. No significant differences in ΔmMASI were observed across melasma patterns (malar vs mixed, P = .197) or Fitzpatrick skin types (III vs IV, P = .497). However, male patients exhibited a significantly greater median improvement than female patients (−2.70 [IQR −4.50 to −1.43] vs −1.65 [IQR −2.35 to −1.20]; P = .039).

Table 4.

Change in mMASI (Δ = Post–Pre) by Subgroups

Subgroup	n	Median (IQR) Δ mMASI	P-value
Melasma pattern
Malar	41	−2.10 (−3.60 to −1.20)	.197
Mixed	9	−1.50 (−1.80 to −0.60)
Fitzpatrick skin type
III	40	−1.80 (−3.00 to −1.20)	.497
IV	10	−2.25 (−3.30 to −1.57)
Sex
Female	30	−1.65 (−2.35 to −1.20)	.039*
Male	20	−2.70 (−4.50 to −1.43)

IQR, interquartile range; mMASI, modified Melasma Area and Severity Index. *P < .05.

Exploratory analyses using continuous variables showed that the number of RFMN sessions was strongly correlated with percentage reduction in mMASI (Spearman's ρ = 0.77; P < .001), suggesting a cumulative treatment effect. Baseline mMASI showed only a weak, nonsignificant association with percentage reduction (Spearman's ρ = −0.21; P = .14), indicating that response was not driven solely by mild baseline disease. Patient age was not correlated with treatment response (Spearman's ρ = −0.03; P = .81).

When stratified by RF energy level, the mean percentage mMASI reduction was 42.5% in the low-energy group and 30.6% in the medium-energy group; this difference did not reach statistical significance (Mann–Whitney U, P = .052). Associations between patient satisfaction, AEs, and subgroup characteristics (sex, skin type, and melasma pattern) were not statistically significant (P > .05 in all Fisher's exact tests).

Sensitivity Analyses

To address potential confounding by concurrent topical therapies, 2 sensitivity analyses were performed.

First, we analyzed the 31 patients (62.0%) who received sunscreen only during the RFMN period, representing a functional monotherapy subgroup (ie, RFMN plus photoprotection without any active topical depigmenting agent). In this subgroup, the median mMASI decreased from 6.0 (IQR 4.50-7.8) at baseline to 3.3 (IQR 1.9-5.7) posttreatment (P < .001), with a median percentage reduction of 42.3%.

The subgroup comparison revealed no statistically significant difference between patients receiving RFMN alone with sunscreen (n = 31) and those receiving additional topical agents (n = 18). Baseline and posttreatment mMASI scores were comparable between groups (6.0 [4.5-7.8] vs 6.9 [5.48-8.85], P = .241; and 3.3 [1.95-5.7] vs 3.9 [2.62-5.85], P = .442, respectively). Median percentage mMASI improvement was 42.3% (IQR 14.2-51.9) in the sunscreen-only group and 30.6% (IQR 18.6-61.9) in the adjunctive topical agents’ group (P = .852), with median absolute reductions of −2.1 (IQR −3.0 to −1.2) and −1.8 (IQR −3.98 to −1.28), respectively (P = .663).

Patient-reported satisfaction was documented in 27 of 31 patients (87.1%), and AEs occurred in 4 (12.9%), all mild and self-limited. No significant associations were observed between satisfaction and sex (P = .638), Fitzpatrick skin type (P = 1.000), or melasma pattern (P = .497).

Second, among the patients (n = 10) who used sunscreen or topical agents (Elidel or Lidomex), a significant reduction in mMASI was observed (P = .005), with median scores decreasing from 6.9 (IQR 6.0-8.4) at baseline to 4.5 (IQR 2.7-5.2) posttreatment, corresponding to a 29.2% improvement. Among the 8 patients who used concurrent hydroquinone-based topical depigmenting agents, a significant mMASI reduction was also observed: median mMASI decreased from 6.75 (IQR 4.72-9.00) to 3.60 (IQR 3.07-6.82), with a median change of −1.80 (IQR −2.18 to −1.50; P = .014; Figure 6).

Figure 6.

Subgroup analysis (modified Melasma Area and Severity Index [mMASI] change): pre- and posttreatment mMASI scores stratified by adjunctive therapy subgroups: sunscreen only (n = 31), hydroquinone (n = 8), other topical agents (sunscreen, Elidel, or Lidomex cream; n = 10), and no topical adjuncts (n = 1).

One patient received RFMN without any adjunctive topical therapy, including sunscreen; baseline mMASI decreased from 9.6 to 8.4 (Δ mMASI = −1.2; 12.5% reduction). Given n = 1, this case is reported descriptively and is not intended to support inferential conclusions; rather, the sunscreen-only subgroup (n = 31) serves as the primary approximation of POTENZA RFMN functional monotherapy.

DISCUSSION

This retrospective, pre–post observational study demonstrates that POTENZA RFMN produces clinically meaningful improvements in melasma severity in a real-world setting. The median mMASI reduction of −1.80 (32.3% of improvement) was accompanied by physician-rated improvement in 98% of patients (72% moderate to marked), patient satisfaction in 90%, and only mild, self-limited AEs. These results are particularly noteworthy given that the cohort was predominantly Fitzpatrick type III, a group in which the risk of postinflammatory hyperpigmentation with energy-based devices is well recognized.^22,27

The magnitude of improvement we observed is consistent with published data on RFMN for melasma. A split-face controlled trial reported significant improvements in melanin index and mMASI at 6 months, and a prospective study showed a 64% reduction in mMASI following conventional therapy combined with RFMN maintenance.^28,29 Jung et al found that RFMN combined with Q-switched Nd:YAG laser produced superior results compared with laser alone, suggesting additive benefits of RFMN on dermal targets.³⁰ What distinguishes our findings is their real-world nature, reflecting the variability inherent in routine clinical practice where treatment parameters are individualized rather than strictly standardized.

The proposed mechanisms by which POTENZA RFMN addresses melasma likely extend beyond thermal injury to melanocytes. Current evidence indicates that dermal remodeling plays a central role in melasma pathogenesis, with increased vascularity, solar elastosis, and senescent fibroblast accumulation contributing to sustained pigmentary abnormalities.^2,3 Delivery of controlled thermal energy to the dermis through insulated microneedles targets deeper structural abnormalities while sparing the epidermis. The resulting neocollagenesis and vascular remodeling may disrupt the inflammatory microenvironment that perpetuates melasma.^20,21 In addition, transepidermal elimination through microneedle channels may facilitate melanin clearance, as suggested by electron microscopy studies showing loosening between melanocytes and adjacent epidermal cells.³⁰

One of the most intriguing findings was the significant sex-based difference in treatment response, with men demonstrating nearly double the median mMASI reduction compared with women. Although melasma is overwhelmingly more common in women, our cohort included 20 male patients, a substantial representation that allowed meaningful statistical comparison.³¹ Hormonal factors, particularly estrogen and progesterone, are well-established contributors to melasma persistence in women, with elevated estrogen receptor expression documented in lesional skin.^32,33 Increased estradiol, luteinizing hormone, and follicle-stimulating hormone levels have also been reported in women with melasma, potentially creating a more refractory phenotype.³⁴ Men with melasma may represent a phenotype driven more heavily by photoaging and vascular components precisely the targets of radiofrequency technology.^35,36 Future prospective studies should stratify outcomes by sex and explore whether hormonal status influences the efficacy of POTENZA RFMN.

The safety profile observed reinforces the utility of POTENZA RFMN in skin of color. With only 12% of patients experiencing AEs, all mild, self-limited, and resolving within 1 week, our results compare favorably with reported complication rates of traditional laser modalities. The absence of significant postinflammatory hyperpigmentation or prolonged erythema is particularly reassuring. This favorable safety margin likely reflects the design advantage of insulated RFMN delivery, which concentrates thermal energy in the dermis while minimizing epidermal heating.^18,20

This is also in line with broader systematic review evidence in facial rejuvenation, which has described RFMN as a generally well-tolerated procedure associated predominantly with mild, transient AEs.³⁷ A systematic review and qualitative evidence synthesis specifically focused on RFMN for melasma similarly reported a consistently favorable safety profile across heterogeneous clinical studies, with low incidence of postinflammatory hyperpigmentation in darker phototypes.¹⁹ Other systematic reviews of RFMN in skin of color concluded that these modalities demonstrate a low risk of scarring or hyperpigmentation in Fitzpatrick types III to VI, with the key determinants being appropriate energy settings and experienced practitioners.^37–39 Nonetheless, clinicians should remain vigilant, as even transient inflammation can occasionally trigger pigmentary changes in susceptible individuals; conservative parameter selection and rigorous photoprotection counseling may have contributed to the low AE rate in our cohort.

The lack of significant differences in treatment response across melasma patterns or Fitzpatrick phototypes suggests that POTENZA RFMN may offer relatively uniform efficacy across clinical subtypes. However, our cohort was heavily weighted toward malar pattern (82%) and Fitzpatrick type III (80%), limiting statistical power to detect subtype-specific effects.

A central interpretive challenge of any retrospective single-arm study of melasma is distinguishing the effect of the investigational intervention from that of concurrent therapies and natural disease fluctuation. Although a nonrandomized design cannot definitively resolve this, several converging lines of evidence in our data support a genuine contribution of POTENZA RFMN to the observed improvement. First, we observed a clear dose–response relationship between the number of RFMN sessions and the magnitude of percentage mMASI reduction (Spearman's ρ = 0.77; P < .001), a pattern that would be unexpected if improvement were driven primarily by photoprotection or natural regression. Second, mMASI reduction remained statistically significant and consistent across both sensitivity analysis groups supporting the robustness of the findings. Excluding patients who received active topical depigmenting agents yielded a median mMASI reduction of 38.1%, while the more stringent functional monotherapy subgroup (sunscreen only, n = 31) achieved a comparable median reduction of 42.3%. Third, the absence of a significant association between baseline severity and percentage improvement (ρ = −0.21; P = .14) argues against the observed effect being an artifact of a preponderance of mild disease. Taken together, these findings suggest that RFMN contributes meaningfully to the observed clinical improvement, while acknowledging that the absolute effect size attributable to the device alone can only be quantified in a prospective controlled trial.

We recognize several limitations. The retrospective design introduces selection bias and precludes causal inference. Patients received individualized treatment parameters and variable concurrent topical regimens, and although exact dosages and application frequencies of topical agents were not fully documented, all regimens had been stable for at least 4 weeks before RFMN and throughout the study period. The absence of a control group limits our ability to distinguish the effect of RFMN from natural disease fluctuation. The predominance of mild-to-moderate baseline disease (median mMASI 6.15) likely reflects a referral pattern toward patients who had plateaued on conservative treatments but had not reached severe refractory disease; this may limit the generalizability of our findings to severe or refractory melasma. Follow-up was relatively short for a chronic relapsing condition, with a median of 6 months (IQR 3-9 months) postfinal treatment. Additionally, mMASI, while validated and reproducible, remains a subjective tool; the study would have benefited from objective colorimetric or Visia imaging.^5,6

Despite these limitations, this study contributes meaningfully to the evidence base supporting RFMN as a useful tool in the melasma armamentarium, particularly in Fitzpatrick type III patients. The high patient satisfaction rate of 90% reflects not only clinical improvement but also the procedure's tolerability and acceptability.

Several research priorities emerge. Prospective randomized controlled trials comparing POTENZA RFMN with established treatments such as low-fluence Q-switched lasers will help position RFMN within evidence-based algorithms.^1,17 Head-to-head comparisons of monopolar vs bipolar modes, with and without PLLA or HA boosters, will help optimize protocol selection.²⁴ Longer follow-up studies tracking recurrence rates over 12 to 24 months are needed to address durability, and incorporation of objective colorimetric imaging (eg, Visia) will enhance objective outcome assessment. Investigation of predictive biomarkers, demographic, hormonal, or histopathological, could enable precision-medicine approaches that target RFMN to those most likely to benefit.

CONCLUSIONS

POTENZA RFMN achieved meaningful mMASI reductions, high physician-rated improvement, high patient satisfaction, and only mild, self-limited AEs in this predominantly Fitzpatrick type III cohort of patients with melasma. The absence of significant differences by melasma pattern or phototype, together with greater responses in men, suggests that treatment algorithms may be refined beyond traditional distribution-based classifications. Prospective, randomized controlled trials with longer follow-up and objective colorimetric outcome measures are needed to validate these findings and to optimize treatment parameters.

Disclosures

Drs H.-B. Kim and Lee have received research grants from Jeisys Medical Inc. (Seoul, Republic of Korea). Ms Baek and Dr Kumar are employed by Jeisys Med Inc., Seoul, Republic of Korea.

Funding

This research was supported by funding from Hallym University, Seoul, Republic of Korea. Jeisys Med Inc. (Seoul, Republic of Korea) funded the open-access publication of this manuscript.