Thermage FLX vs Volnewmer: two monopolar radiofrequency devices compared
Medically reviewed by Dr Sin Yong · Last reviewed · 8 min read
Published 9 October 2026 · Reviewed by Dr Sin Yong
Thermage FLX, made by Solta Medical, and Volnewmer, made by CLASSYS in Korea, are both non-invasive monopolar radiofrequency devices that heat the deeper dermis through the skin surface to tighten it. They run at the same frequency. They differ in how they cool the skin, in their regulatory wording, and in how they feel.
Short answerBoth deliver monopolar radiofrequency at 6.78 MHz. Thermage FLX cools with cryogen spray; Volnewmer with continuous water cooling. In a 2025 randomised split-face trial in 22 Asian women at equal power density, lifting, skin volume and wrinkle results were comparable and Volnewmer was significantly less painful. In their US filings, Thermage FLX carries wrinkle indications; Volnewmer is cleared for electrocoagulation and haemostasis.
CLASSYS, Korea; monopolar RF, 6.78 MHz; water cooling; FDA K240248 (2024), predicate Thermage FLX
Head-to-head trial
Randomised split-face, 22 Asian women: comparable lifting and wrinkle results; Volnewmer significantly less painful (Roh 2025)
FDA wording
Thermage FLX: includes non-invasive treatment of wrinkles and periorbital wrinkles. Volnewmer: electrocoagulation and haemostasis of soft tissue
Used here
Volnewmer, within the VF Lift – Vertical Facelift; Dr Sin Yong is a CLASSYS Key Opinion Leader
Disclosure. Dr Sin Yong is an international Key Opinion Leader for CLASSYS, the maker of Volnewmer, and uses Volnewmer within his VF Lift – Vertical Facelift protocol. This page compares the two devices from their US FDA filings and a published randomised trial; it does not rank one above the other.
Thermage FLX and Volnewmer compared from their FDA filings
Electrocoagulation and haemostasis; non-invasive treatment of wrinkles and rhytids, including periorbital
Electrocoagulation and haemostasis of soft tissue
How do they work?
Monopolar radiofrequency passes current from a treatment tip on the skin to a return pad elsewhere on the body. Tissue resistance turns that current into heat in the deeper dermis and the fibrous septa beneath it, which contracts existing collagen and prompts new collagen to form over the following months. The surface is protected by cooling while the deeper layers heat. Both devices work this way at the same frequency, 6.78 MHz.
Monopolar RF heats the deeper dermis in bulk while the surface is cooled.
What did the head-to-head trial find?
A prospective, randomised, single-blind split-face trial treated 22 Asian women once, with Volnewmer on one side and Thermage FLX on the other at equal power density, and followed them for eight weeks. It measured pore size, elasticity, skin density, fine lines, lifting, investigator-rated improvement and pain, and examined collagen and elastin ex vivo. The authors reported comparable lifting, skin volume and wrinkle results between the two, with significantly less procedural pain on the Volnewmer side (Roh, Ann Dermatol 2025). It is one trial, of one session, with short follow-up.
What do the FDA filings say?
Thermage FLX’s 2017 filing includes indications for the non-invasive treatment of wrinkles and rhytids, including periorbital wrinkles on the upper and lower eyelids. Volnewmer’s 2024 filing, which named Thermage FLX as its predicate device, is cleared for electrocoagulation and haemostasis of soft tissue, without wrinkle wording. A filing describes what a manufacturer submitted data for in the US; it is not a measure of how a device performs against another.
In lean faces, the aim is tightening without taking away the fat that supports the face.
How Volnewmer is used here
Dr Sin Yong uses Volnewmer as the core of his VF Lift – Vertical Facelift, a protocol for lean or hollow faces where tightening is wanted without removing volume. For puffier or heavier faces he generally uses Time Freeze Laser LCLR® instead.
“Same frequency, different cooling. In lean Asian faces I want the heat in the dermis, not in the fat that is holding the face up.”
They are different devices from different makers that use the same technology, monopolar radiofrequency at 6.78 MHz. Thermage FLX cools with cryogen spray; Volnewmer with continuous water cooling.
In one randomised split-face trial in 22 Asian women, lifting, skin volume and wrinkle results were comparable after one session at equal power density, with less pain on the Volnewmer side. It is a single, short trial.
In the 2025 split-face trial, procedural pain was significantly lower on the Volnewmer side. Comfort also depends on settings, area and the individual.
Volnewmer has US FDA 510(k) clearance (K240248, 2024) for electrocoagulation and haemostasis of soft tissue, with Thermage FLX as its predicate device. Thermage FLX’s clearance includes wrinkle indications.
Volnewmer, as the core of his VF Lift – Vertical Facelift. He is an international Key Opinion Leader for CLASSYS, its maker.
References
Roh H, Lee YI, et al. Monopolar radiofrequency with water cooling versus cryogen cooling: a prospective randomised split-face trial in 22 Asian women. Ann Dermatol. 2025;37(6):397-407. doi:10.5021/ad.25.166. source
US FDA 510(k) summary K170758 — Thermage FLX (Solta Medical), 2017: 6.78 MHz; indications include non-invasive treatment of wrinkles and periorbital wrinkles. source
US FDA 510(k) summary K240248 — Volnewmer (CLASSYS), 2024: monopolar RF, 6.78 MHz; indication: electrocoagulation and haemostasis of soft tissue; predicate Thermage FLX. source
Chandra S, et al. Physics of fractional microneedle radiofrequency. J Cutan Aesthet Surg. 2024;17:177. doi:10.25259/jcas_98_23 (PMID 39483649). source
