By Daebbang
“I’ve been looking into radiofrequency lifting. Some clinics put a patch on your body and some don’t. I’ve also heard there is radiofrequency done with needles. What is the difference?”
Radiofrequency lifting is a treatment that passes an electric current through the skin to create heat inside the tissue, and that heat makes collagen tighten and form anew. Heat is produced because the tissue the current passes through resists the flow of electricity[1]. Collagen that is heated shrinks on the spot, and afterward the skin makes new collagen[2].
Radiofrequency is a treatment that makes mildly to moderately sagging skin a little firmer, and it does not lift the skin dramatically the way surgery does[3]. In this article I will explain step by step what radiofrequency does inside the skin, why some radiofrequency treatments use a patch on the body and others do not, and which concerns needle-free and needle radiofrequency each suit.
What Is Radiofrequency?
Radiofrequency (RF) is an electric current that changes direction very rapidly. RF devices send this kind of current into the skin. The skin and the tissue beneath it slightly resist the current as it passes, and at that moment electrical energy turns into heat. It works on a principle similar to the way an electric blanket warms up with electricity. That is why RF heat forms broadly along the path the current travels[1].
This is where it differs from HIFU (high-intensity focused ultrasound, e.g., Ultherapy). HIFU focuses ultrasound on a single point inside the skin, like a magnifying glass, to create a tiny heat point. Needle-free RF heats the dermis under the electrode and the tissue beneath it broadly, as if it were one layer[1]. A Korean study that compared skin tissue after the two treatments also found that new collagen formed in a narrow area of a deep layer with HIFU, and in a broad area across several layers of the dermis with monopolar RF[4]. The principle of HIFU is covered in detail in the article I Keep Hearing About Ultherapy. What Exactly Is It?
What Happens in Skin That Has Been Heated?
Two things happen when skin is heated. First, the collagen fibers in the dermis shrink from the heat, and the tissue tightens a little right away. Next, the skin treats this heat stimulus like a wound, and while it heals it makes new collagen. In a study that examined RF-treated skin under an electron microscope, the shape of the collagen fibers changed and the gene signals that make collagen increased[2].
So the effect of RF does not end on the day of treatment. In a study of 86 people who had a single treatment around the eyes, the researchers interpreted the change as a slight tightening right after treatment followed by further tightening over several months, in step with the time it takes the wound to heal[5]. How collagen is rebuilt and how far apart treatments should be are covered in detail in the article Can Frequent Thermage or RF Skin Tightening Make Your Skin Thinner?
Why Do Some RF Treatments Use a Patch on the Body?
An electric current flows only when the path out and the path back are connected. RF devices are divided into monopolar and bipolar types depending on how many electrodes they have, and whether a patch is used comes from this difference[1, 6].
Monopolar RF has only one electrode at the tip of the treatment device. So a wide patch is placed on another part of the body as the place for the current to return to. This patch is called a return electrode. The current travels from the device tip through the body and back to the patch, and this completes the circuit[1, 6]. The patch has low resistance where it touches the skin, so it produces almost no heat, and heat is produced where the high-resistance device tip touches the skin[7]. Because the current passes deep through the body, it can heat relatively deep layers[1].
Bipolar RF has two electrodes at the device tip. The current travels only between the two electrodes, so there is no need to attach a separate patch. Heat forms in the shallow layer between the two electrodes and, in theory, reaches at most about half the distance between the two electrodes. The depth is usually about 1 to 4 mm, shallower than monopolar RF, but the area that is heated is easier to control[1]. Multipolar RF, with three or more electrodes, works on the same principle: current flows between the electrodes without a patch[1].
A single device does not always use only one mode. Some needle RF devices let the operator choose between monopolar and bipolar modes. According to clearance documents from the U.S. Food and Drug Administration (FDA), such a device uses a patch in monopolar mode, and in bipolar mode it passes current between neighboring needles without a patch[7]. So whether a patch was used is not enough to judge the type of device or its effect.
How Do Needle-Free RF and Needle RF Differ?
Needle-free RF (e.g., Thermage) is applied to the skin surface and passes current through it to heat the dermis and the tissue beneath it broadly. The skin is cooled during treatment so that the surface does not get too hot[1, 2]. In a study of 86 people who had a single treatment around the eyes with an early device, after 6 months of follow-up the wrinkle score on photographs improved by 1 point or more in 83.2% of the treated eye areas, and 61.5% of the eyebrows rose by 0.5 mm or more. Redness and swelling after treatment were mild, and about half of the participants were satisfied with the results[5]. A systematic review of monopolar and bipolar RF studies also found measurable improvement in sagging skin of the face and body[8]. However, an analysis of 25 randomized studies of cosmetic RF found many limitations in the study methods, and the evidence was not sufficient to judge it better than other treatments[9].
Needle RF (e.g., Potenza) inserts very fine needles into the skin and passes current directly into the dermis through the needles. With devices whose needles are coated so that electricity does not pass through their surface, energy comes out only at the needle tips, and heat forms mainly at the tips. Skin that has not been heated remains between the needles and helps recovery[1]. The U.S. clearance document for one device states that the needle insertion depth can be adjusted from 0.5 mm to 2.5 mm or 4 mm, depending on the tip[7]. A systematic review of studies in which 558 people (20 studies) received needle RF found improvement in skin texture and firmness[10]. Another systematic review covering a range of skin conditions found that the reduction in acne scars was similar to that with fractional lasers[11].
| Needle-free RF (e.g., Thermage) | Needle RF (e.g., Potenza) | |
|---|---|---|
| Principle | The device is applied to the skin surface and current heats the skin broadly[1] | Needles are inserted into the dermis and current is passed through them. Insulated needles create heat at the needle tips[1] |
| Where heat forms | Broadly across the dermis and the tissue beneath it, as if it were one layer[1] | Small points inside the dermis where the needles reach[1, 7] |
| Concerns it suits | Mild to moderate skin sagging, fine wrinkles[5, 8] | Skin texture, fine wrinkles and firmness, acne scars[10, 11] |
| Recovery | Redness and swelling are mild and brief[5] | Redness and swelling last from a few hours to a few days[10] |
| Common side effects | Pain during treatment, temporary swelling[12] | Redness, swelling, small scabs, temporary pigmentation[10] |
Who Is It Suited For?
RF works in skin with sagging up to a moderate degree, and it is hard to expect the kind of change that a surgical lift brings[3]. Needle-free RF suits people whose jawline has started to loosen a little and who have begun to notice fine wrinkles[5, 8]. Needle RF is often used for people who are more concerned about skin texture or acne scars than sagging. There are also reports that needle RF improved sagging and firmness, so the concerns the two types suit partly overlap[10, 11]. In analyses of randomized studies comparing RF with lasers for acne scars, the reduction in scars was similar or slightly greater with lasers, but fractional and needle RF caused less pigmentation, and redness lasted a shorter time[13, 14].
Some RF devices cannot be used if you have an electrical device inside your body, such as a pacemaker[12]. Before treatment, please tell your doctor about any devices implanted in your body, treatments you have had recently, illnesses you currently have and medicines you are taking.
Does It Hurt? Are There Side Effects?
With needle-free RF, there is mild to moderate pain during treatment, and it usually stays in the treated area only while the treatment is being done. Swelling usually subsides within 5 days[12]. Pain with needle RF varied from study to study. In one study the average was 3.4 out of 10, but in another study many people felt moderate or greater pain, and the area around the eyes hurt more[10]. Redness and swelling were the most common and subsided within a few hours to a few days. Small scabs can form, and when pigmentation occurred it was temporary[10].
Rarely, serious side effects such as burns, scars, changes in which fat is lost or the skin surface becomes uneven, and nerve damage have also been reported[5, 8, 12, 15, 16], so it is best to have treatment after a thorough consultation with an experienced doctor.
So What Should I Do?
| Situation | What to do | Reason |
|---|---|---|
| When your jawline has started to loosen a little | Needle-free RF is worth discussing. Check the change with photos after a few months | A slight tightening right after treatment followed by further tightening over several months has been reported[5] |
| When skin texture or acne scars concern you more than sagging | Needle RF is worth discussing | Skin texture and acne scars improved[10, 11] |
| When sagging has progressed considerably | Rather than having RF many times, first discuss whether another treatment is needed | RF works in skin with sagging up to a moderate degree[3] |
| When you have an electrical device inside your body, such as a pacemaker | Be sure to tell your doctor before treatment | Some devices cannot be used in this case[12] |
| When you want to know whether a patch will be used | Ask which type of RF it is | Monopolar RF uses a patch and bipolar RF does not[1, 7] |
Take-home messages
- Radiofrequency lifting is a treatment that passes an electric current through the skin to create heat inside the tissue, and that heat makes collagen shrink and form anew.
- While HIFU concentrates heat on a single point inside the skin, RF broadly heats the layers the current passes through.
- Monopolar RF uses a patch on the body to give the current a path back, and bipolar RF does not need a patch because the current flows only between the two electrodes at the device tip.
- Needle-free RF is mainly used for skin sagging and fine wrinkles, and needle RF mainly for skin texture and acne scars, and the concerns they suit partly overlap.
- RF suits mild to moderate sagging and cannot replace surgery.
- Redness, swelling and pain during treatment are common, and needle RF can cause small scabs. Rarely, serious side effects such as burns, scars and nerve damage have also been reported, so it is best to have treatment after consulting an experienced doctor.
References
[1] Zhang B, Tan X, Zhang Q, Wu M. The Landscape of Radiofrequency Technology for Skin Rejuvenation. Health Science Reports. 2025;9(1):e71575. DOI: 10.1002/hsr2.71575
[2] Zelickson BD, Kist D, Bernstein E, et al. Histological and ultrastructural evaluation of the effects of a radiofrequency-based nonablative dermal remodeling device: a pilot study. Archives of Dermatology. 2004;140(2):204–209. DOI: 10.1001/archderm.140.2.204
[3] Fritz K, Tiplica GS, Salavastru C. Radiofrequency: Monopolar, bipolar, multipolar and fractional. Dermatologie (Heidelberg). 2023;74(10):740–747. DOI: 10.1007/s00105-023-05202-w (article in German; English abstract reviewed)
[4] Suh DH, Choi JH, Lee SJ, et al. Comparative histometric analysis of the effects of high-intensity focused ultrasound and radiofrequency on skin. Journal of Cosmetic and Laser Therapy. 2015;17(5):230–236. DOI: 10.3109/14764172.2015.1022189
[5] Fitzpatrick R, Geronemus R, Goldberg D, et al. Multicenter study of noninvasive radiofrequency for periorbital tissue tightening. Lasers in Surgery and Medicine. 2003;33(4):232–242. DOI: 10.1002/lsm.10225
[6] Taheri A, Mansoori P, Sandoval LF, et al. Electrosurgery: part II. Technology, applications, and safety of electrosurgical devices. Journal of the American Academy of Dermatology. 2014;70(4):607.e1–607.e12. DOI: 10.1016/j.jaad.2013.09.055
[7] U.S. Food and Drug Administration. 510(k) Summary K231216: POTENZA. 2023. https://www.accessdata.fda.gov/cdrh_docs/pdf23/K231216.pdf Accessed 2026-11-06. (clearance summary submitted by the manufacturer)
[8] Rohrich RJ, Schultz KP, Chamata ES, et al. Minimally Invasive Approach to Skin Tightening of the Face and Body: Systematic Review of Monopolar and Bipolar Radiofrequency Devices. Plastic and Reconstructive Surgery. 2022;150(4):771–780. DOI: 10.1097/PRS.0000000000009535
[9] Oliveira Paggiaro A, Pinheiro R, Soares K, et al. Evaluation of the evidence level for the use of radiofrequency in aesthetic treatments: A systematic review and meta-analysis. Journal of Cosmetic Dermatology. 2021;20(9):2691–2702. DOI: 10.1111/jocd.14353
[10] Kumar N, Suh DH, Lee SJ, et al. Radiofrequency Microneedling for Facial Rejuvenation: A Systematic Review. Journal of Cosmetic Dermatology. 2026;25(4):e70845. DOI: 10.1111/jocd.70845 (two authors are employees of a needle RF device manufacturer; one is a speaker for the same company)
[11] Kumar N, Kim HM, Nishikawa A, et al. Effectiveness of Radiofrequency Microneedling in the Treatment of Dermatological Conditions: A Systematic Review. Aesthetic Plastic Surgery. 2026;50(13):5282–5317. DOI: 10.1007/s00266-026-05834-y (the first author is an advisor to a needle RF device manufacturer; two authors are speakers for the same company)
[12] Solta Medical. Thermage FLX Indication and Important Safety Information. https://soltaspace.solta.com/aspx/ImportantSafetyInformation Accessed 2026-11-06. (manufacturer’s safety information)
[13] Li J, Duan F, Kuang J. Meta-analysis of fractional radiofrequency treatment for acne and/or acne scars. Journal of Cosmetic Dermatology. 2022;21(12):6754–6766. DOI: 10.1111/jocd.15348
[14] Argobi Y, Tobeigei F, Alasiri FI. Fractional CO2 Laser Versus Micro Needling Radiofrequency for Post Acne Scarring: A Meta-Analysis of RCTs. Journal of Cosmetic Dermatology. 2026;25(3):e70765. DOI: 10.1111/jocd.70765
[15] Camacho-Hubbard I, Ibrahimi OA, Mariwalla K, Munavalli G. Safety Considerations and Complications With Radiofrequency Microneedling: A Cross-Sectional Analysis of the US FDA MAUDE Database. Dermatologic Surgery. 2026;52(9):867–872. DOI: 10.1097/DSS.0000000000005251
[16] U.S. Food and Drug Administration. Potential Risks with Certain Uses of Radiofrequency (RF) Microneedling: FDA Safety Communication. 2025-10-15. https://www.fda.gov/medical-devices/safety-communications/potential-risks-certain-uses-radiofrequency-rf-microneedling-fda-safety-communication Accessed 2026-11-06.
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