Thermage or Ulthera: which layer does each treat?

By Dr. Young Jun Kim, Medical Director, Violacell Plastic Surgery · Board-certified plastic surgeon (Korea)

Thermage FLX works mainly on the skin itself: it uses monopolar radiofrequency to warm a broad volume of the dermis and the fibrous strands just beneath it, which suits firmness, fine lines and thin eyelid skin. Ulthera works deeper and more precisely: it focuses ultrasound into small points at set depths, down to the supporting layer called the SMAS, and shows the tissue on screen while it treats. Which one fits depends on which layer of your face has changed, and many faces need both.

The face ages in layers

A face is built from five layers: skin, the fat just under the skin (subcutaneous fat), the muscle and its supporting layer (the SMAS, or superficial musculoaponeurotic system), the deep fat pads, and bone. All five change with age, but not at the same speed or in the same way in every person. Dr. Kim writes that lifting treatment should start by looking at every layer to find the cause, and then responding to that cause (clinic blog, 2025).

Layer	What tends to change	What reaches it
Skin (dermis)	Thinner, less firm, fine lines, crepey texture	Thermage; Ulthera at 1.5 and 3.0 mm; skin boosters such as Re2O
Subcutaneous fat	Heavier along the jowls in some, thinner in others	Ulthera can place energy in this layer; liposuction for localized excess
SMAS and muscle	The support layer loosens and slides down	Ulthera at 4.5 mm; surgery for marked descent
Deep fat	Deep fat pads shrink or shift, cheeks flatten	Volume support such as Sculptra
Bone	Gradual change in the facial framework	Not reached by these devices; volume can compensate partly

Real faces mix several of these changes, which is why the examination comes before the choice of device. See the five layers of facial aging.

How Thermage delivers heat

Thermage FLX, made by Solta Medical, is a monopolar radiofrequency device. Current passes from a disposable tip on the skin to a return pad elsewhere on the body, and the tissue's resistance turns it into heat. The heat spreads through a broad zone of the dermis and the fibrous septae, the connective tissue strands that anchor skin to the layers below.

A cooling spray protects the surface with each pulse. Existing collagen contracts at once, and a healing response builds new collagen over the following months. Different tips treat different areas: larger tips for the face, jawline and neck, and a small Eye Tip for the eyelids. There is no imaging; a grid on the skin and your feedback on the heat guide coverage.

How Ulthera delivers heat

Ulthera (also called Ultherapy) uses microfocused ultrasound with visualization. Instead of warming a broad zone, it focuses energy into tiny points in a row at one fixed depth set by the transducer:

4.5 mm: the SMAS, the layer a surgical facelift also works on
3.0 mm: the deep part of the dermis
1.5 mm: the upper dermis, used for texture in some areas

Because the handpiece shows a live ultrasound image, the practitioner can see the layers, the thickness of the soft tissue and where bone lies close to the surface. Dr. Kim plans Ulthera from that image together with palpation, feeling the tissue by hand, and combines the three depths for each face. How the depths differ is covered in What do Ulthera's 4.5, 3.0 and 1.5 mm depths each do?

Side by side

	Thermage FLX	Ulthera
Energy	Monopolar radiofrequency	Microfocused ultrasound
Heating pattern	Broad, even warming of a volume	Separate small points at one depth
Main layer	Dermis and fibrous septae just below	SMAS and dermis, by transducer
Imaging	No	Yes, real-time ultrasound
Main aim	Firmer, smoother skin; eyelid skin	Lift of the deeper support layer, plus skin firming
Sensation	Brief deep heat, then cooling	Sharper, deeper heat, strongest over bone

Signs the skin layer is the main problem

Thermage is more likely to be the main tool when the change is in the skin rather than in the structure under it:

fine lines and a crepey look, especially around the eyes and on the cheeks
skin that feels thin and less springy when pinched
a general loss of firmness without heavy jowls
upper eyelid skin that looks slightly loose but does not rest on the lashes

In his answers to patients, Dr. Kim explains that when fine wrinkles and skin elasticity are the goal, radiofrequency devices such as Thermage are better suited to building collagen in the dermis than focused ultrasound, which works deeper (signed answers to patients, 2026).

Signs the deeper layer is the main problem

Ulthera is more likely to be the main tool when the support beneath the skin has loosened:

a jawline that has lost its sharp edge, with early jowling
softness under the chin and along the upper neck
a brow that sits slightly lower than before
cheeks that look better when gently pushed up toward the temple

Even here, the plan is not automatic. Dr. Kim has written that two people who both want a slimmer jawline may need different things: one needs the SMAS lifted, another needs the fat layer reduced, and the salivary glands and chewing muscle change the plan again (column, 2025).

When the two are combined

Because they work on different layers, Thermage and Ulthera are often planned together: Ulthera for the deeper support, Thermage for the skin over it. Combining them adds time, discomfort and cost, so it makes sense when both layers have clearly changed, not as a default package. The order and spacing are planned so that swelling from one treatment does not distort the assessment for the next, and they are decided at consultation for each person.

When the skin itself is thin or dull, a skin booster such as Re2O may be added; when volume has been lost, Sculptra may be. How the three treatments fit into one plan is described in How are Ulthera, Sculptra and Thermage combined in one plan?

How long each effect lasts

Both treatments work through collagen remodeling, so results appear gradually, usually over about two to six months. Dr. Kim writes that energy devices do not make collagen themselves; they prompt the body's own healing response, and that regeneration unfolds over weeks to months (clinic blog, 2025).

In his answers to patients he has described the effect of Thermage as typically lasting around ten months to a year, and Ulthera as holding for around six months. Other sources give different ranges; the real figure depends on age, skin and the amount treated, and is not guaranteed.

Limits and risks

Neither device removes excess skin, repositions tissue that has descended well below its original place, or replaces lost volume. Some people see only a small change, and some see no visible change.

Thermage: brief heat with each pulse, redness and swelling for hours, occasional temporary grid marks, rare blisters or burns, and rare small surface dents. It is generally not used with a pacemaker or other implanted electronic device.
Ulthera: discomfort especially over bone, redness, swelling and tenderness for days, occasional bruising or raised lines, rare temporary nerve irritation, and rare burns. In very lean faces some people worry about a hollower look, so deep energy is placed conservatively.

Tell the clinic about pregnancy, implants, recent fillers or threads and blood-thinning medicines.

Who neither suits well

If jowls hang clearly below the jawline, the neck skin is loose and folded, or the upper eyelid skin rests on the lashes, a device is unlikely to give the change you want. A mini facelift, facelift, upper eyelid surgery or forehead lift is usually the more effective answer. Dr. Kim trained in facial surgery and will tell you when that is the case, although he does not perform surgery at Violacell. More on this in When is non-surgical lifting not enough?

Why it matters who plans it

Thermage and Ulthera are the same machines wherever they are used. What differs is the reading of the face that decides which one, where and how much. Dr. Kim completed his plastic surgery residency at Chonnam National University and served there as a clinical professor, so he has seen the SMAS, the ligaments and the fat compartments directly in surgery. He designs Ulthera from the ultrasound image and palpation, explains why radiofrequency suits the skin layer better, and lectured to about 100 clinicians in 2026 on stepwise combination treatment for skin quality. Why Dr. Kim for Thermage · Why Dr. Kim for Ulthera

Common questions

Is Thermage or Ulthera better?

Neither is better in general. Thermage mainly firms the skin with radiofrequency, while Ulthera reaches the deeper SMAS layer with focused ultrasound and imaging. The right choice depends on which layer has changed, and some faces need both.

Which hurts more, Thermage or Ulthera?

People describe Thermage as a brief deep heat followed by cooling, and Ulthera as a sharper, deeper heat that is strongest over bone. Discomfort varies between people, and numbing cream or other comfort measures are usually used for both.

Can Thermage and Ulthera be done together?

Yes. They are often combined so that Ulthera treats the deeper support layer and Thermage treats the skin. The order and spacing are decided at consultation, and combining them makes sense only when both layers have changed.

Which one is better for fine lines?

For fine wrinkles and skin elasticity, radiofrequency such as Thermage is generally better suited than focused ultrasound, which works deeper. Thin, crepey skin may also benefit from a skin booster.

Can either one replace a facelift?

No. Both can firm tissue that is still roughly in place, but neither can remove excess skin or reposition tissue that has descended far. When sagging is marked, a mini facelift or facelift is usually the more effective option.