Effects by HIFU Tip Depth and a Guide to Handpieces by Area

Hello, I’m the chief director of Diore Clinic at Gangnam Station.

"I want to get HIFU lifting, but where exactly do 1.5mm, 3.0mm, and 4.5mm work?"

"Ulthera, Shurink, and CoolSonic are all HIFU, right? What’s different if the handpiece is different?"

These are questions I hear every day in the clinic. HIFU (High Intensity Focused Ultrasound) uses the same basic principle, but the effects vary completely depending on which depth tip is used and where the energy is delivered. Today, from the perspective of a skincare specialist, I’ll organize the expected effects by tip depth and the facial areas each handpiece is applied to.

The Core Principle of HIFU: Changes Created by 'Thermal Coagulation Points'

HIFU works by concentrating ultrasound energy at a specific depth within the skin, like focusing sunlight to a single point with a magnifying glass, creating a 60~70°C thermal coagulation point (TCP, Thermal Coagulation Point). This microscopic thermal damage triggers the body’s natural wound-healing response, producing new collagen and elastin as the tissue contracts, resulting in lifting and tightening effects.

The important point is that the skin layer stimulated and the expected effect differ depending on the depth at which the TCP is formed. That is why HIFU devices come with various cartridges (tips) for different depths.

Target Skin Layers and Expected Effects by Tip Depth

1.5mm — Upper Dermis (Epidermis-Dermis Junction)

This is the shallowest tip depth, stimulating the upper dermis close to the skin surface.

• Main effects: improved skin texture, reduction of fine lines, minimized pores, more even skin tone
• Suitable areas: thin-skin areas such as around the eyes, forehead, and around the mouth
• Features: rather than lifting, this is closer to a skin renewing (skin regeneration and texture improvement) effect. It is especially useful in areas where deeper tips are hard to use, such as just above the eyelids or around the lips, where the skin is very thin.

In Shurink Universe, a dedicated Derma Shurink tip is applied at this depth, forming thermal points only in the upper dermis without affecting the fat layer to improve skin elasticity.

2.0mm — Mid Dermis (Shurink Universe Exclusive)

This is a newly added depth in Shurink Universe and corresponds to the Eye Shurink tip.

• Main effects: tightening for the eye area, improvement of under-eye wrinkles, and reduction of outer corner sagging
• Suitable areas: delicate areas that need careful treatment, such as around and under the eyes
• Features: it stimulates the dermis slightly deeper than 1.5mm while delivering energy optimized for the thin skin around the eyes.

3.0mm — Lower Dermis (Deep Dermis)

This is a key mid-depth tip that targets the collagen-dense zone in the lower dermis.

• Main effects: skin tightening, increased collagen density, improved elasticity, refined pores, reduced fine lines
• Suitable areas: areas with moderate skin thickness such as the cheeks, jawline, forehead, and neck
• Features: in a histological study published in the 2025 Journal of Cosmetic Dermatology, it was confirmed that after HIFU treatment at a 3.0mm depth, collagen types I and III synthesis and elastin fibers increased significantly in the dermis. It plays a key role in increasing skin density and creating a firm, elastic feel.

4.5mm — Fascia Layer (SMAS, Superficial Musculoaponeurotic System)

This is the deepest tip, delivering ultrasound energy to the SMAS layer, which is directly manipulated in facelift surgery.

• Main effects: powerful lifting, improvement of cheek and jawline sagging, V-line contouring, and reduction of double chin
• Suitable areas: cheeks, jawline, neck, and other thicker skin areas with noticeable sagging
• Features: the SMAS layer is a fibrous connective tissue that links the skin and muscles, and when this layer contracts, the entire skin is physically pulled upward. That is why the 4.5mm tip is called the core of lifting. However, because the energy reaches deeper, pain tends to be stronger than at other depths and may be felt more clearly in areas close to bone.

Note: If the 4.5mm tip is used indiscriminately in areas with thin fat or existing hollows, a gaunt-cheek (fat loss) side effect may occur. For this reason, accurate anatomical judgment by the practitioner is extremely important.

Comparison Table of Effects by Tip Depth

Features of Handpieces and Area-Based Application by Major HIFU Devices

Ultherapy (Ultherapy)

Developed by the U.S. company Merz, this is the world’s first ultrasound lifting device and the gold standard of HIFU approved by the FDA.

• Handpieces (transducers): three types, 1.5mm / 3.0mm / 4.5mm
• Biggest strength: with the patented DeepSEE™ real-time ultrasound imaging technology, it delivers energy while directly checking the depth and structure of the skin layers on the monitor during the procedure. As a 'HIFU you can see while shooting,' it offers the highest precision and safety.
• Area-based application: forehead and brow lifting (1.5mm), cheek and jawline tightening (3.0mm), lower-face and neck lifting (4.5mm)
• Duration of effect: about 12~18 months, with treatment recommended once a year
• Effectiveness and safety have been proven in more than 110 clinical papers.

Shurink Universe (Shurink Universe)

A second-generation HIFU device developed by Korea’s Classys and approved by the Ministry of Food and Drug Safety.

• Handpieces: dual system of the existing handpiece (ULTRA F) + pen-type handpiece (ULTRA BOOSTER)
• Cartridges: 7 types in total (4 ULTRA F cartridges: 1.5mm / 2.0mm / 3.0mm / 4.5mm + 3 booster-only cartridges: 1.5mm / 3.0mm / 4.5mm)
• Biggest strength: the pen-type booster handpiece enables delicate treatment on curved areas such as the glabella, eye area, philtrum, and chin tip. In addition, the existing dot type now includes MP mode (line form), creating about 400 thermal coagulation points densely in one shot.
• Area-based application:
• Duration of effect: about 3~6 months, with treatment recommended 2~3 times a year

CoolSonic (CoolSonic)

A next-generation domestic HIFU device that promotes 'pain-free HIFU.'

• Handpieces: dual system of Line type + Pen type
• Biggest strength: the patented ACC™ (Active Conduction Cooling) cooling system and TDT thermal diffusion technology are the core features. The cooling module built into the handpiece instantly cools the skin surface at the same time as the ultrasound energy is delivered, dramatically reducing pain compared with conventional HIFU.
• Area-based application:
• Duration of effect: about 6~12 months
• It is a good alternative for those who wanted the effect of Ultherapy but hesitated because of pain.

Comparison Table of Devices and Handpieces

Recommended Tip Depth and Expected Effects by Facial Area

Forehead and brows: 1.5mm (skin texture) + 3.0mm (tightening) → brow lift, reduced forehead wrinkles

Eye area: 1.5mm or 2.0mm → improvement of fine lines around the eyes, lifting of sagging outer eye corners (deep tips are not used around the eyes)

Cheeks and cheekbones: 3.0mm (dermal tightening) + 4.5mm (SMAS lifting) → improvement of cheek sagging, reduction of nasolabial folds

Jawline and double chin: 4.5mm (SMAS lifting) + 3.0mm (dermal reinforcement) → V-line contour, reduction of double-chin volume, more defined jawline

Neck: 3.0mm + 4.5mm → improvement of neck wrinkles, tightening of loose neck skin

In actual treatment, it is not a matter of using only one depth in one area; rather, tips of multiple depths are combined layer by layer to deliver energy from the dermis to the SMAS in a multi-layered way. This is the 'multi-layer approach' of HIFU, and it is why the practitioner’s experience and judgment determine the outcome.

Frequently Asked Questions (Q&A)

Q1. Do I have to receive all 1.5mm, 3.0mm, and 4.5mm?

It is not necessary to use every depth. The optimal combination of depths varies depending on skin thickness, amount of fat, degree of sagging, and the desired effect. For example, if you have thin skin and hollow cheeks, it is safer to minimize the use of 4.5mm and focus on 1.5mm and 3.0mm.

Q2. Is Ultherapy more effective than Shurink or CoolSonic?

All three devices use the same HIFU principle. Ultherapy offers high precision with real-time image guidance (DeepSEE™) and has been verified by more than 110 clinical papers, so the effect and duration from a single treatment tend to be longer. Shurink and CoolSonic cause less pain and are less expensive, making them suitable for regular maintenance treatments.

Q3. Can HIFU make the cheeks look sunken?

The ultrasound energy from the 4.5mm tip can pass through the fat layer and affect fat cells. If treatment is performed at high power in areas with little fat, gaunt cheeks may occur, so it is important to use the 4.5mm tip only in areas with sufficient fat and avoid areas at risk of hollowness.

Q4. When do the effects of HIFU appear?

You may feel slight tightening from tissue contraction immediately after the procedure, but the main effect appears at its maximum 2~3 months later, when collagen regenerates. Improvement then continues gradually up to 6 months.

Q5. Can Thermage and HIFU be done together?

Yes, it is a very good combination. HIFU lifts the deep SMAS layer, while Thermage (radiofrequency) stimulates collagen in the dermis for tightening. To use an analogy, HIFU supports the building’s steel frame, while Thermage reinforces and finishes the exterior walls.

Q6. Is CoolSonic really not painful?

It is true that the pain is significantly reduced compared with conventional HIFU. The ACC™ cooling system instantly cools the skin surface, blocking heat and pain. In most cases, the procedure can be done without anesthesia, and the sensation is usually only mild warmth and soreness.

Conclusion

Even with the same device, HIFU results vary greatly depending on tip depth and area selection. Refining skin texture with 1.5mm, firming the dermis with 3.0mm, and lifting the fascia layer with 4.5mm — this multilayer approach is the secret to natural yet effective lifting.

Most important of all is choosing the depth and device that suit your skin condition, and receiving treatment from experienced medical staff who understand anatomical structures accurately. If you are curious about HIFU lifting, please feel free to book a consultation. After directly assessing your skin thickness and degree of sagging, we will suggest the optimal treatment plan.

References

1. Kim HJ, et al. Do Different High-Intensity-Focused Ultrasound Frequencies Have Different Effects? A Histological Analysis Correlated With Patients' Subjective Assessments. J Cosmet Dermatol. 2025;24(2):e14506.
2. MacGregor JL, Tanzi EL. Microfocused ultrasound for skin tightening. Semin Cutan Med Surg. 2013;32:18-25.
3. Official Ultherapy clinical data: more than 110 clinical papers (60 peer-reviewed + 50 clinical studies).
4. Classys Shurink Universe official product information: 7-cartridge system, MFDS approved.
5. Fabi SG. Noninvasive skin tightening: Focus on new ultrasound techniques. Clin Cosmet Investig Dermatol. 2015;8:47-52.