RF Microneedling for Acne Scars, Infini vs Secret RF

Written by Dr Bernard Ong Medically reviewed by Dr Bernard Ong Expert opinion by Dr Bernard Ong

Dr Bernard Ong is an aesthetic doctor at The Clifford Clinic with 16 years of experience treating acne and acne scars, having personally treated over 5,000 cases of acne and over 3,000 cases of acne scars. More about Dr Bernard Ong.

Radiofrequency (RF) microneedling is one of the most important tools for depressed acne scars. The two systems patients ask about most are Infini and Secret RF. They are not interchangeable. The difference between insulated and non-insulated needles, and the energy each delivers, decides which one is chosen. This article explains both with the FDA figures and how the choice is made. It builds on our complete acne scar treatment guide, what causes acne scars, the types of acne scars, acne scars vs hyperpigmentation, do acne scars go away and laser treatment for acne scars.

 

How RF microneedling works

Fine needles deliver radiofrequency energy directly into the dermis, heating it in a controlled way and triggering new collagen and elastin. Over the following weeks and months that collagen remodels, filling and lifting depressed scars from below while refining the surface.

Because the heat is delivered through needles rather than across the skin surface, RF microneedling is generally safer in pigmented and Asian skin than older fully ablative lasers, an important advantage in Singapore. The differences that matter between devices are how much energy they deliver, how deep, and whether the needles are insulated.

 

Insulated versus non-insulated needles

This is the central distinction. Infini uses insulated needles, which concentrate the energy at the needle tip deep in the dermis while sparing the upper layers of skin. That places high energy exactly where a deep scar needs rebuilding, with a strong safety margin for the surface, which is also why it is the safer choice in darker skin tones.

Secret RF uses non-insulated needles, which deliver energy along the whole shaft. That is gentler on the deep dermis but has a distinct advantage of its own. The energy passes through the oil gland and helps calm it.

 

The figures that matter

For depressed scars, the maximum power a device can deliver is the specification that most determines the result, and here the FDA filings are clear. Infini’s generator delivers up to around 50 W (FDA 510(k) K121481) through its 49-pin handpiece, and Secret RF is cleared to a maximum of 25 W (FDA 510(k) K170325). For comparison, the gentler Sylfirm X, excellent for pigment and pores, is cleared to just 16 W (FDA 510(k) K213612), which is why it is not relied on for deep scar remodelling. That device is covered specifically in is Sylfirm X good for acne scars, the full Sylfirm X vs Secret RF vs Infini comparison, and why power matters in RF microneedling.

 

Why Secret RF suits acne-prone skin

The first question with any scar patient is whether the acne is still active, since most patients still have some ongoing breakouts. When it is active, Secret RF is the device of choice. Its non-insulated needles pass through and calm the oil gland, decreasing oil-gland activity and helping bring the acne under control while it works on texture. It is the one RF scar treatment genuinely safe for acne-prone skin. When acne control is poor, it is combined with AGNES RF on the same day, which targets the oil glands directly. This is a capability Infini, for all its depth and power, does not share.

 

Why Infini for deep scars and darker skin

When the acne is settled and the priority is deep remodelling, particularly in a patient with a darker skin tone, Infini is favoured. The insulated needles deliver that higher 50 W energy deep into the dermis while protecting the epidermis, which lowers the risk of post-inflammatory hyperpigmentation. In these patients, Infini is often paired with injectables such as Rejuran, Sculptra, Juvelook or RE20, which gives the best overall result while keeping the pigmentation risk low. Our acne scar treatment for dark skin guide expands on this.

 

Combining RF with PDRN and other modalities

RF microneedling is rarely the whole answer. PDRN, or Rejuran, is an excellent addition to either device. It reduces downtime by improving healing and potentiates the result, and it can be performed together with microneedle fractional RF. Tethered rolling scars still need subcision to release the bands, and deep ice pick scars need TCA CROSS. In practice, subcision is often sequenced with Secret RF first, then fractional CO2 about a month later. The combination logic is in subcision and fillers for rolling scars and combination therapy.

 

Limitations and common patterns

RF microneedling has clear limits. It cannot improve keloid scars, and it is not very effective for temple scars. The two patterns that bring disappointed patients in are an underpowered machine and repeated monthly sessions that cost a great deal for little result. Both come down to insufficient energy and insufficient recovery time. Deliver proper energy with the right device and space sessions four to six weeks apart rather than crowding in many gentle treatments. For another candid take, see Genius RF vs Infini.

 

What a typical RF programme looks like

To make this concrete, a representative programme might rotate modalities over about six months. A session of Infini, a session of Secret RF, and a couple of fractional CO2 sessions, spaced four to six weeks apart, with PDRN added to support healing and biostimulators where volume or specific scar types call for them. Without injectables, that kind of rotation typically delivers around twenty to thirty per cent improvement; with them, more. The exact mix depends on the scar types and skin tone, but the principle is steady, staged progress rather than an intensive blitz.

Downtime varies by device. RF microneedling usually involves a day or two of redness and minor swelling, less than ablative laser, which is part of why it is so useful in working patients and in darker skin. It is always better to deliver proper energy with a sensible recovery window than to chase a no-downtime session too gentle to remodel a scar. The recovery time is when the collagen is actually being built.

 

Clinical summary

Infini and Secret RF are both excellent, but they are different tools. Secret RF, non-insulated and cleared to 25 W, is the choice for acne-prone skin because it calms the oil gland. Infini, insulated and reaching around 50 W, is the choice for deep remodelling and darker skin. The gentler 16 W Sylfirm X belongs to pigment and pores, not deep scars. The right device depends on your acne, scar type and skin tone, ideally chosen in person. Continue with subcision and fillers for rolling scars or acne scar treatment for dark skin.

 

Frequently Asked Questions

What do Koreans do for acne scars?

Korean aesthetic practice popularised much of modern scar treatment using RF microneedling (such as Secret RF and Sylfirm X), fractional lasers, subcision, and PDRN (Rejuran), usually in combination. Dr Ong uses the same evidence-based modalities, matched to each patient’s scar type and skin tone.

Can Rejuran be combined with RF microneedling?

Yes. PDRN (Rejuran) is an excellent add-on to microneedle RF such as Infini or Secret RF. It reduces downtime by improving healing and potentiates the result, and it can be performed alongside the RF treatment.

Is Infini or Secret RF better for acne scars?

Neither is universally better. Secret RF (non-insulated, FDA-cleared to 25 W) is preferred for acne-prone skin because it calms the oil gland. Infini (insulated, around 50 W) is preferred for deep remodelling and darker skin. The choice depends on acne status, scar type and skin tone.

Is RF microneedling safe for dark skin?

Generally yes, and insulated Infini is the safest option because its insulation spares the epidermis while delivering deep energy, lowering the risk of post-inflammatory hyperpigmentation. Settings are still chosen carefully for darker skin.

Device specifications & sources

• S. FDA 510(k) Summary K213612 (SYLFIRM X, ViOL Co., Ltd.): Output power Max 16 W at 50 Ω; 2 MHz; bi-polar RF.
• S. FDA 510(k) Summary K170325 (Secret RF, Ilooda Co., Ltd.): Max power Max 25 W at 500 Ω; 2 MHz; needle depth 0.5-3.5 mm.
• S. FDA 510(k) K121481 (INFINI, Lutronic Inc.): insulated RF microneedling system, 49-pin handpiece, maximum RF generator output approximately 50 W.

 

Written, medically reviewed and expert opinion by Dr Bernard Ong, The Clifford Clinic. This article is for general education and reflects Dr Ong’s clinical experience treating acne scars in Singapore. It is not medical advice. Treatment suitability, results, downtime and cost vary between individuals. Please arrange a consultation for advice specific to your skin.