Home›Blog›Skin›Infini vs Secret RF for Acne Scars: Which Device, and Why
Written by Dr Gerard Ee, MBBS (UK), MRCS (Edinburgh), Postgraduate Diploma in Practical Dermatology (Cardiff). Founder and Medical Director, The Clifford Clinic and The Clifford Surgery, Singapore.
Infini and Secret RF are the two radiofrequency microneedling systems I use for acne scars. They are not interchangeable, and choosing between them is a clinical decision rather than a matter of brand preference. The difference between insulated and non-insulated needles, and the energy each delivers, decides which is the better choice for a given patient.
With more than 10 years’ experience of Infini, I have found that the two devices separate most often on one question: whether the acne that produced the scars is still active. Where it is active, non-insulated Secret RF is the correct starting point. Where it is settled and the scars are deep, insulated Infini is. The device sets the ceiling on what a course can achieve rather than guaranteeing the result. For the procedure itself, prices and aftercare, read the RF microneedling guide for Singapore; for every scar treatment matched to scar type, see acne scar removal in Singapore.
This page is one part of my acne scar treatment guide for Singapore, which covers every scar type and every treatment option.
Infini vs Secret RF: the main differences
Infini and Secret RF are both radiofrequency microneedling devices for acne scars; they differ mainly in needle design and how much energy each can deliver. Secret RF is the starting point where acne is still active, and Infini where the acne has settled and the scars are deep. Both are spaced four to six weeks apart.
| Question | Infini | Secret RF |
|---|---|---|
| Needle design | Insulated: energy concentrated at the needle tip, surface spared | Non-insulated tip, which I use for acne-prone skin: energy along the whole shaft1 |
| FDA-cleared maximum output | About 50 W (K121481) | 25 W (K170325) |
| Best suited to | Deep boxcar and rolling scars once acne has settled | Active or recurring acne with texture and scarring, often with AGNES the same day |
| Pigment-prone and darker skin | Preferred: the insulation keeps heat off the epidermis | Settings matched to pigment history |
| Downtime | About 3 days of mild redness | 3 to 4 days of mild scabbing |
| Treatment details | Infini sessions, recovery and quotation | Secret RF sessions, recovery and fees |
Tethered rolling scars and narrow ice pick pits need subcision or TCA CROSS whichever device is chosen.
Insulated versus non-insulated needles
This distinction is the substance of the whole comparison. Infini uses insulated needles, which concentrate energy at the tip deep in the dermis while sparing the surface, so high energy can be placed exactly where a deep scar needs it, with a strong safety margin. This is the reason it is the preferred choice in darker skin, where surface heat is what drives pigmentation.
Secret RF with a non-insulated tip delivers energy along the whole shaft. That is gentler on the deep dermis but carries a distinct advantage, since the energy passes through and calms the oil gland on its way. Cutera also makes semi-insulated Secret RF tips1; for acne-prone skin I use the non-insulated tip.
With more than 10 years of the insulated system, I have found the difference shows most in deep boxcar and rolling scars, where the energy has to arrive at depth without the surface heating that limits how hard a non-insulated device may safely be driven. Neither design is superior in the abstract, and the insulation is an advantage only when the scar is deep enough to require it.
Infini 50 W, Secret RF 25 W: the power figures that matter
For depressed scars, the maximum power a device can deliver is the specification that most determines the result, and the FDA filings are clear. Infini’s generator reaches up to around 50 W (FDA 510(k) K121481). Secret RF is cleared to 25 W (K170325), half that ceiling, and the reason it is not the device chosen when deep remodelling is the priority. For context, Sylfirm X is cleared to 16 W (K213612), which is why it is not a reliable choice for deep remodelling, as set out in why Sylfirm X gives no results on acne scars.
The figure that counts is the ceiling rather than the setting used on the day, because a device cleared to 25 W cannot be driven to the depth an insulated 50 W system reaches, however many sessions are added. Of the patients who consult me after a course of radiofrequency microneedling that produced nothing, a substantial share were treated on a device whose cleared maximum was never going to remodel the scars they present with. Cleared power is nonetheless a ceiling and not a promise, and a well-judged 25 W treatment on the right patient outperforms a poorly judged 50 W one.
Sylfirm X, Secret RF and Infini specifications
| Specification | Sylfirm X | Secret RF | Infini |
|---|---|---|---|
| Manufacturer | ViOL | Ilooda / Cutera | Lutronic |
| Maximum RF output (FDA) | 16 W at 50 Ω | 25 W at 500 Ω | About 50 W, 49-pin |
| FDA 510(k) clearance | K213612 | K170325 | K121481 |
| Needle type | Non-insulated | Non-insulated (semi-insulated tips also made) | Insulated |
| Frequency | 2 MHz | 2 MHz | 1–2 MHz class |
| Needle depth | 0.3–4.0 mm | 0.5–3.5 mm | Up to about 3.5 mm |
| Design focus | Pigment, vessels, pores | Texture, scars, acne control | Deep atrophic scars |
Why Secret RF suits acne-prone skin
My first question in any scar patient is whether the acne is still active, because many patients continue to break out while believing the acne has resolved. When it is active, Secret RF is the appropriate choice, since its non-insulated needles pass through and calm the oil gland while improving texture, which makes it the one radiofrequency scar treatment suited to acne-prone skin.
This is the basis of my signature combination of AGNES plus Secret RF, performed together, which brings the acne under control and resurfaces the rough texture at the same time. It is the pattern I rely on for the many patients whose acne has never quite gone away. Where the scars are deep as well, Secret RF remains the correct starting point while the deep remodelling waits until the acne has settled. How I assess ongoing breakouts is set out in how I approach acne treatment.
Why Infini suits deep scars and darker skin
When the acne is settled and the priority is deep remodelling, especially in darker skin, Infini is the preferred device rather than one of two equivalent options. Its insulated needles deliver that higher 50 W energy deep into the dermis while protecting the epidermis, which lowers the risk of pigmentation in skin that pigments readily. In these patients Infini is often paired with injectables such as Rejuran, PLLA, Juvelook or an ECM booster. The acne scars in darker skin guide expands on this.
I have found that the insulation counts for most in the patients with the least margin for error, those with deeper skin tones and deep atrophic scarring. Deeper or more extensive scarring still needs more sessions, and the improvement accrues over the months after each session rather than during the appointment, so the correct device does not shorten the timeline.
How needle depth is chosen on Infini and Secret RF
Needle depth is matched to the depth of the scar and to the area being treated. Thicker skin with deep cheek scarring can take deeper penetration, whereas thinner skin, such as around the temples, is treated more conservatively, which is one reason temple scars respond poorly to either system. A session works across the area in several passes at varying depths, and those passes are where the two systems diverge: an insulated needle allows the deepest pass to be driven harder than a non-insulated needle safely permits.
Depth is the setting patients never ask about and, in my experience, the one that most decides the result, since the same device set too shallow for the scar produces the underpowered outcome described above. What a session involves, from numbing to aftercare, is on the RF microneedling guide.
Combining Infini or Secret RF with Rejuran, subcision and TCA CROSS
Radiofrequency microneedling is rarely the whole answer, and neither device changes that. PDRN (Rejuran) is a useful addition to either device, reducing downtime and potentiating results, and it can be given alongside the RF in the same visit. The micro-channels also carry healing-focused agents applied immediately afterwards, such as PDRN, exosomes or growth factors. An adjunct of this kind supports a result rather than producing one, and nothing applied through the channels compensates for a device that did not deliver enough energy.
Tethered rolling scars are not lifted by energy delivered from above and need subcision. Deep ice pick scars sit outside what either device reaches and need TCA CROSS. A typical sequence begins with subcision to release the tethered scars, with Secret RF at the next visit once the release has settled, and fractional CO2 about a month later, as covered in subcision for rolling scars. The comparison between the two systems therefore decides the backbone of a plan rather than the plan itself. The error I see most often in a previous plan is a single device used across every scar type on one face, and no choice between Infini and Secret RF corrects it.
What the research shows on RF microneedling for acne scars
A systematic review of 16 studies and 481 patients concluded that fractional RF microneedling is an effective, well-tolerated monotherapy for acne scars6. In a split-face randomised trial, microneedle fractional RF reduced ECCA acne-scar scores by about 46%7, an average on a grading scale rather than a promise that half the scarring is removed. A comparative randomised trial found microneedle fractional RF improved both acne and acne scars, partly by reducing sebaceous gland activity4, the clinical basis for using non-insulated Secret RF when acne is still active.
A 2025 split-face trial comparing non-insulated microneedle RF with ablative fractional CO2 found comparable efficacy with less pain, shorter recovery and significantly less post-inflammatory hyperpigmentation on the RF side8. RF microneedling is reported as safe across skin types including Fitzpatrick type VI5, one reason insulated Infini is relied on in darker skin, and the 2022 international consensus positions RF microneedling and fractional lasers as front-line, often combined options9. Microneedling and CO2 laser play complementary roles3; how RF compares with conventional needling is covered in how effective microneedling is for acne scars.
The evidence covers radiofrequency microneedling as a category rather than one branded system against another, so the choice between Infini and Secret RF rests on needle design and cleared output rather than on a head-to-head trial.
Limitations and common mistakes with RF microneedling
Radiofrequency microneedling cannot improve keloid scars and is only marginally effective for temple scars whichever device is used. Two patterns account for most disappointed patients: an underpowered, weak microneedle RF machine that produced little, and weekly or fortnightly repeated RF that delivered very little while costing a great deal. Both come down to insufficient energy and insufficient recovery time. Delivering proper energy and spacing sessions four to six weeks apart consistently outperforms crowding gentle treatments together. A frequent appointment feels like faster progress while being the slower route to a result.
Infini and Secret RF downtime, sessions and spacing
Downtime is modest by comparison with ablative resurfacing: about 3 days of mild redness after Infini, and 3 to 4 days of mild scabbing after Secret RF. Gentle skincare with sun protection is all that is generally needed. Scar treatment is a course rather than a single session, typically several sessions spaced four to six weeks apart so that each session’s collagen can mature before the next. The interval is the part of the plan patients most often ask to shorten, and shortening it is the reliable route to spending more and gaining less.
RF microneedling also carries risks including burns and scarring; the FDA has reported fat loss and nerve injury with certain uses2. These risks need a procedure-specific discussion rather than an assumption that either brand is risk-free. Before repeating treatment, compare photographs in similar lighting after the agreed review period. Complete scar removal cannot be guaranteed.
The bottom line: Infini or Secret RF
Infini and Secret RF are both capable systems built for different jobs, and the comparison has an answer rather than a preference. Secret RF, non-insulated and cleared to 25 W, is the correct device where the acne is still active, because the energy travels along the whole shaft and calms the oil gland. Infini, insulated and reaching around 50 W, is the correct device where the acne is settled and the scars are deep, and it is the safer of the two in darker skin because the insulation keeps the heat off the surface. Where both conditions are present the acne is brought under control first and the deep remodelling follows. What the choice of device cannot do is guarantee the size of the result, which depends on the depth and mix of scars and on the recovery time allowed between sessions. The complete picture across every scar type is in my acne scar treatment guide for Singapore.
Also considering Sylfirm X? I do not provide it; read what Sylfirm X is actually good for and why Sylfirm X gives no results on acne scars.
Dr Gerard Ee, Aesthetic Doctor in Singapore
Dr Gerard Ee is an aesthetic doctor in Singapore and the Medical Director of his practice at 50 Raffles Place. He graduated from St George’s, University of London, trained in surgery at Singapore General Hospital and the National University Hospital, and holds the MRCS (Edinburgh) and a postgraduate diploma in practical dermatology from Cardiff University.
He has practised aesthetic medicine since 2012, is the author of sixteen peer-reviewed papers, and writes and medically reviews every article on this site. Read more about Dr Gerard Ee.
Arrange an acne scar assessment
Dr Gerard Ee consults and performs Infini and Secret RF acne scar treatment at The Clifford Clinic, 50 Raffles Place, Singapore. Consultations are by appointment. Message the clinic on WhatsApp, or call 6532 2048.
Arrange an assessment with Dr Gerard Ee to discuss Infini, Secret RF and the alternatives for your scars. Bring details of previous procedures and any persistent reactions so the next step can be considered in context.
Infini vs Secret RF FAQs
What do Koreans do for acne scars?
Korean practice popularised much of modern scar treatment: RF microneedling, fractional lasers, subcision and PDRN (Rejuran), usually in combination. The same evidence-based modalities are used here, matched to each patient’s scar type and skin tone, so the question that decides a plan is which device suits the skin being treated rather than where the protocol originated.
Can Rejuran be combined with Infini or Secret RF?
Yes. PDRN (Rejuran) is a useful addition to either device and the choice of radiofrequency system does not change its role. It reduces downtime and potentiates results, and it can be given alongside the RF treatment in the same session.
Is Infini or Secret RF better for acne scars?
Neither device is better for every patient, and the answer follows the state of the acne. Secret RF (non-insulated, 25 W) is the choice where the acne is still active, because its energy travels along the whole shaft and calms the oil gland. Infini (insulated, around 50 W) is the choice where the acne is settled and the scars are deep, and it is also the safer option in darker skin. Where the scars are deep and the acne is still active, the acne is brought under control first and the deep remodelling follows.
Is RF microneedling safe for dark skin?
Radiofrequency microneedling is generally safe in dark skin, and insulated Infini is the safest of the options because its insulation spares the epidermis while delivering deep energy, which lowers the risk of post-inflammatory hyperpigmentation. Safety across skin types describes how the energy is delivered rather than an absence of risk, so sessions are still spaced four to six weeks apart and the energy is matched to the depth of the scar.
Sources
Show the 9 references and device specifications
- Cutera. Secret RF product brochure: tip options.
- U.S. Food and Drug Administration. Potential risks with certain uses of radiofrequency (RF) microneedling. Safety communication, 15 October 2025.
- Meghe S, et al. Efficacy of microneedling and CO2 laser for acne scar remodelling: a comprehensive review. Cureus. 2024. PubMed 38558661.
- Min S, et al. Comparison of fractional microneedling radiofrequency and bipolar radiofrequency on acne and acne scar, and investigation of mechanism: comparative randomised controlled clinical trial. Arch Dermatol Res. 2015. PubMed 26472097.
- Battle F, et al. Clinical evaluation of safety and efficacy of fractional radiofrequency facial treatment of skin type VI patients. J Drugs Dermatol. 2018. PubMed 30481955.
- Niaz G, Ajeebi Y, et al. Fractional radiofrequency microneedling as a monotherapy in acne scar management: a systematic review of current evidence. Clin Cosmet Investig Dermatol. 2025;18:19-29. PubMed 39781098.
- Efficacy of microneedle fractional radiofrequency combined with topical insulin for facial atrophic acne scars: split-face randomised trial. J Cosmet Dermatol. 2025. PubMed 39970082.
- Qu L, Sha S, He C, et al. Comparison of non-insulated microneedle fractional radiofrequency and ablative fractional carbon dioxide laser for facial atrophic acne scars. Acta Derm Venereol. 2025. PubMed 40568948.
- Salameh F, Shumaker PR, Goodman GJ, et al. Energy-based devices for the treatment of acne scars: 2022 international consensus recommendations. Lasers Surg Med. 2022;54(1):10-26. PubMed 34719045.
Device specifications
- U.S. FDA 510(k) Summary K213612 (SYLFIRM X, ViOL Co., Ltd.): output power max 16 W at 50 Ω, 2 MHz, bipolar RF.
- U.S. FDA 510(k) Summary K170325 (Secret RF, Ilooda Co., Ltd.): max power 25 W at 500 Ω, 2 MHz, needle depth 0.5–3.5 mm.
- U.S. FDA 510(k) K121481 (INFINI, Lutronic Inc.): insulated RF microneedling, 49-pin handpiece, maximum RF generator output approximately 50 W.
