What is Thermage? Monopolar RF Technology Explained

Written by Delight Dermatology editorial team · Medically reviewed by Lead Dermatologist, Delight Dermatology Clinic (Korean Board-Certified Dermatologist, AAD International Fellow, ASLMS) · Last reviewed 2026-05-23

Thermage FLXis a fourth-generation non-invasive skin-tightening device manufactured by Solta Medical (Bausch Health) that delivers monopolar capacitive radiofrequency to heat the dermis (about 2.5–3 mm deep), inducing collagen remodeling. First FDA-cleared in 2002 for periorbital wrinkles, Thermage now treats face, neck and body areas. The FLX generation adds AccuREP impedance feedback and a vibrating handpiece that substantially reduces discomfort versus the earlier Thermage CPT (Dover & Zelickson, 2007).

Thermage is a non-invasive skin-tightening treatment that uses monopolar capacitive radiofrequency (RF) to deliver controlled heat into the dermis. It is manufactured by Solta Medical, a Bausch Health company, and has been continuously developed since the original device received its first FDA clearance for periorbital wrinkles in 2002. The current generation is Thermage FLX, the fourth iteration of the platform.

How monopolar capacitive RF actually works

Radiofrequency energy at therapeutic settings warms tissue by oscillating polar molecules — primarily water — in a fast alternating electric field. In a monopolar configuration there is a single active electrode at the treatment tip and a separate return electrode elsewhere on the body; current passes through the tissue between them. The capacitive coupling in Thermage means the tip itself does not contact tissue with bare metal — energy is delivered through a dielectric layer, which produces a more uniform heating profile in the dermis than direct conductive contact. A cryogen spray cools the epidermis on each pulse so that the heat is concentrated in the deeper layer rather than the surface.

The clinical target is the reticular dermis, a layer rich in fibroblasts and the collagen scaffolding that gives skin its firmness. Heating this layer to a controlled temperature range triggers two effects: an immediate contraction of existing collagen fibres and, over the following months, a slow remodeling response in which fibroblasts lay down new, organised collagen. The visible result — a firmer, slightly tighter surface — develops over three to six months rather than appearing on the day. The remodeling timeline and the collagen response have been characterised in the peer-reviewed literature on monopolar RF since the mid-2000s (Dover & Zelickson, 2007; Sukal & Geronemus, 2008; Lolis & Goldberg, 2012).

The Thermage FLX generation: what is new

Thermage FLX, released around 2017, introduced two practical changes over the previous Thermage CPT generation. The first is AccuREP, which measures the impedance of the tissue under the tip on each pulse and adjusts the delivered RF energy to keep the actual dermal temperature in the intended range. Impedance varies by anatomical area, by skin thickness and by hydration, and AccuREP removes a meaningful source of clinical variability between operators — addressing precisely the kind of operator dependence that earlier surveys of monopolar RF identified as a determinant of outcome (Dover & Zelickson, 2007). The second is a vibrating handpiece, which uses gate-control sensory physiology — competing afferent input — to make each pulse substantially more comfortable than on Thermage CPT, and which has reduced the routine use of oral analgesia during treatment.

FDA clearance history

The first Thermage clearance, in 2002, was for the non-invasive treatment of periorbital wrinkles and rhytids — the area around the eyes, where the depth of the skin and the proximity of the orbital rim make laser-based wrinkle treatments more limited. Subsequent clearances expanded the indication to wrinkles and rhytids on the face generally, then to the temporary improvement of the appearance of cellulite, and to non-invasive treatment of skin on the body. The Thermage Eye Tip is specifically designed for the periorbital area, including treatment over closed eyelids when used by a clinician trained in the eye-tip protocol.

Tip families: face, eye, body

Thermage is delivered through interchangeable tips. The face tips are used on cheeks, jawline, lower face and neck. The Eye Tip — smaller, contoured for the orbital rim — is used for upper and lower eyelid skin and the periorbital area; this is what patients usually mean when they ask about "Eye Thermage" — see Delight Dermatology's Eye Thermage procedure detail for the specific eye-area protocol. The body tip is larger, designed for higher pulse counts per session, and is used for the abdomen, inner arms, knees, thighs and similar areas where the treatment surface is broad. Tip choice is part of the consultation plan because it determines tissue depth, total pulse count and the cost band.

What Thermage does well, and what it does not

Thermage produces a measured improvement in dermal firmness and a modest tightening effect — a result consistent with the response documented in monopolar RF cohorts on Asian skin as well (Kushikata et al., 2005). It does not eliminate wrinkles in the way a filler does, and it does not lift sagging tissue in the way a thread or a surgical procedure does — those are different problems with different solutions. The result is not permanent: most patients return for maintenance after one to two years, depending on the original laxity profile and on lifestyle factors such as photoageing exposure. There are no claims here of being the best, the world-class, or the only Thermage practice — these phrases are restricted by Korean medical advertising regulation and are clinically meaningless in any event.

How it differs from Ultherapy

Patients often weigh Thermage against Ultherapy, the microfocused-ultrasound device. The headline difference is depth: Thermage heats the dermis, Ultherapy heats the SMAS — the superficial musculoaponeurotic system, the same fibrous layer that a surgeon mobilises in a facelift. Thermage tightens, Ultherapy lifts. The full comparison, including who should consider combining the two, is on the Thermage vs Ultherapy page. To discuss which device makes sense for a specific laxity profile, see Delight Dermatology's Thermage procedure page for the full session detail.