Ultraformer MPT: What changes with cartridge depth? Selecting the right application based on the layer with sagging

In ultrasonic skin laxity treatment (HIFU) like Ultraformer MPT, the layer being heated changes depending on cartridge depth: 1.5 mm targets the shallow skin layer, 3.0 mm targets the deep skin layer, and 4.5 mm targets the fascia (SMAS) beneath the skin[1]. Research commonly uses a combined approach applying both the deeper 4.5 mm and shallower 3.0 mm[2][3]. No research directly comparing the Ultraformer MPT device itself was found; the explanation here draws from studies of the same type of ultrasonic equipment.

What changes with cartridge depth?

Different depths concentrate heat in different layers. 1.5 mm targets the dermis (the skin proper), 3.0 mm targets the deep dermis, and 4.5 mm targets the layer beneath the skin and the SMAS fascia[1].

Cartridges that reach deeper tissue use lower ultrasound frequencies[4]. Ultrasound that warms the dermis through the fascia is characterized by gradual, natural change[5].

How much does combining depths change results?

Most research applies treatment to both deep and shallow layers. In a 10-person study applying 3.0 mm after 4.5 mm, physicians observed improvement in 80% of participants at 90 days, and 90% reported improvement themselves[2].

In a 20-person study using 4.5 mm and 3.0 mm cartridges, clear tightening appeared in 70% at 3 months[3]. Lower-face volume decreased by 0.29 mL on the treated side and increased by 0.42 mL on the untreated side[3].

Both are small studies and do not compare which depth combination is best[3].

Is a shallower cartridge safer?

Shallower does not necessarily mean safer. In jawline-to-neck treatment, the shallower 3.0 mm cartridge showed higher adverse-event rates, and higher-frequency treatment carries greater tissue-damage risk[6].

The same study reported skin surface injury in 6.67% of participants, which resolved within about a week[6]. Across studies using 1.5 mm, 3.0 mm, and 4.5 mm cartridges, fat atrophy, blistering, bruising, hyperpigmentation, and swelling have been reported[7].

Eye injury has occurred after periocular application[8]. Always confirm beforehand whether treatment near the eyes will be performed.

What are the pain and frequency guidelines?

Pain perception varies across studies. In research without anesthetic pills or injections, pain was 3.00 out of 10[3]. Another study found intratreatment pain mild to moderate, with most posttreatment pain resolving within about 2 days[5].

Conversely, some reviews cite severe pain as HIFU's major drawback[9]. Multiple sessions typically require 1–2 treatments, with some protocols maintaining results through radiofrequency (RF) therapy afterward[9].

Who is and isn't suited to ultrasound?

It suits those with mild sagging and no obvious facial volume loss[10]. The Japan Association of Plastic Surgeons' guidelines note that HIFU is effective for wrinkles and sagging but achieves less improvement than surgery or injection[11].

In cases of hollow cheeks or severe sagging, ultrasound alone may be insufficient[10][11].

What should a consultation confirm to find the right approach for you?

The cartridge combination used depends on whether sagging is in the shallow or deep skin layer[1]. This is difficult to assess with a mirror alone and requires in-person examination.

During consultation, confirm which cartridge depths will be applied where, cheek fat volume, whether periocular application will occur, and pain management strategy.