Thermage FLX Explained: How a Session Runs

Thermage FLX is a monopolar radiofrequency treatment that heats the deep dermis and fibrous septa while cooling the surface, tightening collagen and prompting new collagen over two to six months. A session takes about 45 to 90 minutes: marking, a return pad, then hundreds of pulses with cooling and vibration. It suits mild to moderate skin laxity.

What is Thermage FLX?

Thermage is a monopolar radiofrequency (RF) system that has been used for skin tightening since the early 2000s; FLX is the current generation. In monopolar RF, electrical current flows from the treatment tip on the skin, through the body, to a return pad placed elsewhere, usually on the back or abdomen. As the current passes through the tissue under the tip, the tissue’s resistance turns it into heat. Because the current spreads out as it goes deeper, the heating is volumetric: a broad zone of the deep dermis and the fibrous septa beneath it is warmed, rather than a set of focused points.

Heat does two things. Straight away, it partially contracts existing collagen fibres, which is why some people notice slight firmness on the day. Over the following months, the controlled thermal injury prompts fibroblasts to lay down new collagen. Biopsy studies of monopolar RF have shown collagen changes in the dermis after treatment. The main result therefore builds gradually, typically over two to six months.

The FLX generation added a system that measures the skin’s resistance and recalibrates the energy before each pulse, a larger treatment tip that covers more area per pulse, and vibration to make treatment more comfortable. Thermage FLX is used on the face and jawline, around the eyes, on the neck and on body areas such as the abdomen, arms and thighs. The full service is described on Thermage FLX at IN Eternity Clinic.

How does a Thermage FLX session run, step by step?

1. Assessment and photographs. The face is examined at rest and in movement, from the front and in profile, and photographed in standard lighting. The areas to treat and the number of pulses are agreed.

2. Preparation. Make-up and skincare are removed. Numbing cream may be applied if you prefer it, though many people manage without. A temporary grid is transferred onto the skin to guide even placement of pulses, and the return pad is placed on the body.

3. Setting the energy. A few test pulses are given, and you rate the heat on a simple scale. Energy is adjusted so that each pulse is warm and deep but tolerable. This feedback continues throughout.

4. Treatment passes. Coupling fluid is applied, and the tip is placed on each square of the grid in turn. Each pulse delivers a sequence of cooling, heating and cooling, with vibration. Several passes are made over each area, with extra passes along lines where more tightening is wanted, such as the jawline or under the chin.

5. The eyes, if included. For eyelid treatment a small eye tip is used, after protective shields are placed over the eyes with anaesthetic drops, so that the upper and lower lid skin can be treated safely.

6. Finishing. The grid and fluid are wiped away and moisturiser and sunscreen applied. A full-face session usually takes about 45 to 90 minutes, depending on the areas and number of pulses.

What does Thermage FLX feel like?

Each pulse feels like a brief build-up of deep heat, followed quickly by cooling, with vibration at the same time. Areas over bone, such as the jawline, temples and forehead, tend to feel hotter. The heat is meant to be felt, and the energy is adjusted to your feedback rather than pushed to the maximum: published protocols moved from single high-energy passes to multiple lower-energy passes, which is more comfortable and reduces the risk of side effects.

Afterwards the skin is usually pink and warm for a few hours, sometimes with mild swelling. Tenderness to touch for a few days is possible. Uncommon effects include small temporary bumps or grid marks, small areas of numbness, blisters and, rarely, burns or contour dips in fat. Most people return to work the same day or the next.

Who suits Thermage FLX, and who does not?

Thermage FLX suits mild to moderate skin laxity: early softening of the jawline, crepey skin on the neck, slackening of the lower face, and hooding or crepiness of the eyelid skin. It suits people who want gradual change, without needles in the face and with little interruption to work. It does not replace volume that has been lost from the temples, cheeks or under the eyes, and it cannot match a surgical lift where laxity is marked.

Face shape matters. In a leaner or hollow face, deep heat that tightens can also make hollows look more obvious; hollowing after HIFU, Ultherapy or Thermage in lean faces is a known side effect worth discussing before treatment. At IN Eternity Clinic, lean or hollow faces are usually considered for the VF Lift – Vertical Facelift on CLASSYS Volnewmer, while fuller lower faces are usually considered for Time Freeze Laser LCLR® (Laser Collagen Lipo Remodelling). Thermage FLX is most suited where the main issue is skin laxity in a face with reasonable volume.

Thermage is not used if you have a pacemaker, implanted defibrillator or other implanted electronic device, and it is deferred in pregnancy, over active infection or inflammation, and over areas with recent filler or threads until the timing has been discussed. Metal implants in the treatment area, a history of keloids and conditions that affect healing or sensation are reviewed first.

When do results appear, and how long do they last?

A little firmness can be visible soon after treatment from collagen contraction, but the main change develops over two to six months as new collagen forms. Studies of monopolar RF on the cheeks, neck and around the eyes have reported gradual, measurable tightening in many participants, with variation between people. The fairest way to judge the result is to compare photographs taken in the same lighting at assessment and at review, because slow change is hard to see in the mirror.

How long results last depends on age, skin quality, sun exposure, weight change, smoking and genetics; the face also keeps ageing after treatment. Many people consider a repeat session about once a year, though some wait longer. The comparison with other lifting technologies is set out in Ultherapy vs Thermage vs HIFU, and treatment of the eyelids in particular is covered in Thermage for the eyes.

How does Thermage FLX fit into a plan at IN Eternity Clinic?

At assessment Dr Sin Yong decides which layers of the face have changed — skin, support layer, fat or bone — and recommends Thermage FLX only where skin laxity is the main issue. If fillers or anti-wrinkle injections are also planned, the order is agreed in advance, usually with energy treatment first. The factors that shape cost are explained in Thermage cost in Singapore.

Common myths, answered

• Myth: Thermage gives an immediate facelift.
  Fact: There may be slight early firmness, but the main change builds over two to six months as collagen remodels.
• Myth: Higher heat gives a better result.
  Fact: Protocols moved to multiple passes at tolerable energy. Excess heat raises the risk of burns and fat loss without improving results.
• Myth: Thermage suits every face.
  Fact: In lean or hollow faces, tightening can make hollows look deeper. Face shape and volume are assessed first.
• Myth: Thermage replaces fillers.
  Fact: It tightens skin; it does not restore lost volume. The two address different problems.