The short answer
Plan the whole visit and a way to get help afterwards. Treatment time, preparation and recovery are different parts of the appointment, and your instructions should match the actual procedure you receive.
Reserve time for the full visit
Ultrasound treatment at Glassy takes about 15 minutes. Allow about 30 minutes for treatment with post-treatment soothing care and a soothing mask, without numbing preparation. Consultation and medical examination take additional time.
Optional numbing preparation is individually selected at 20–40 or 40–60 minutes according to skin type, sensitivity and allergy history. A suspected allergy requires assessment before cream is used. Add this preparation time to the approximately 30-minute face treatment-and-care block; consultation and examination are additional. This is not a fixed total appointment duration.
Tell the team about your schedule and numbing preference when arranging the visit. Treatment scope, assessment and any combined procedures may affect timing. An enquiry does not by itself confirm a booking.
Discuss comfort before starting
Numbing cream is optional for LinearZ at Glassy. You may choose treatment with or without it according to your sensitivity and the plan discussed with your dermatologist. Glassy does not use sedation for LinearZ; you remain awake and can describe what you feel.
In our clinic’s experience, discomfort is usually around 4–5/10 without cream and 2–3/10 with cream. On this 0–10 scale, 0 means no pain and 10 the worst pain imaginable. These are clinic experience estimates, not a trial average or a guarantee for your session.
The typical sensation described at Glassy is prickling. Sensitivity differs with the area, amount of fat, settings and individual pain tolerance. Tell the doctor about unexpected, sharp or concerning pain so the treatment can be reassessed. A lower score does not mean a complication is impossible.
Share previous procedures and health information
Prepare the names and dates of fillers, wrinkle-relaxing injections, threads, surgery and energy treatments, together with the areas involved. If you do not know the product, bring a record from the treating clinic where possible.
Tell the dermatologist about medicines, allergies, pregnancy or breastfeeding, implanted devices or metal, active skin problems and previous complications. Do not stop prescribed medicines on your own to fit an appointment. A safety review may mean modifying or postponing treatment.
An online statement that implants or recent procedures never matter is not a substitute for checking the actual device instructions and your history. The FDA’s general therapeutic-ultrasound safety information also discusses skin integrity and implants; it is not a LinearZ-specific protocol.
Source: US FDA · Non-invasive body contouring technologies, ultrasound section.
Distinguish recovery from a result
Redness, swelling, tenderness or bruising can occur after ultrasound treatment. Their likelihood and duration vary with treatment scope and individual response. Ask what to expect for your actual session; this page does not assign an unconfirmed number of downtime days.
General ultrasound safety information includes risks such as burns, blisters and nerve injury. New weakness, worsening pain, blistering or persistent altered sensation should prompt medical advice. Seek local urgent care for severe or rapidly worsening symptoms rather than waiting for a routine message reply.
A treatment-room video or a photograph taken immediately afterwards cannot establish the final result or your likely recovery. Ask for the follow-up plan and keep a record of the treatment you actually received.
Source: US FDA · Non-invasive body contouring technologies, ultrasound section.
Leave with instructions you can use
Before leaving, confirm cleansing, skincare, makeup, sun protection, exercise, heat exposure and pressure on the treated area. A routine for an injectable or another energy device may not be appropriate for the treatment you received.
Ask for the instructions in English and clarify which symptoms should lead you to contact the clinic. Keep your treatment record and contact details accessible. Advice for a combined session needs to account for every procedure in that visit.
Plan follow-up beyond Seoul
Share how long you will remain in Seoul and when you will return home. Ask whether a review is appropriate before departure and how follow-up will work afterwards. Do not assume that one visit guarantees a particular outcome or that a photograph can replace every examination.
For an enquiry, you can use the clinic’s consultation form or WhatsApp English. Confirm contact arrangements and response hours with the team. If a problem develops after you leave Korea, an in-person assessment near you may be needed.
A practical travel plan leaves room for uncertainty. Your consultation should help you weigh the likely benefit, limitations, recovery and follow-up against your own priorities and available time.
Sources and how to read them
- Jeisys Medical · LinearZ product, modes and cartridge specifications
Official product description. Nominal depths below follow its Specifications table; its depth graphic differs, and 0.5-mm steps are described as ACCU-series only. Exact cartridge options need model-specific verification.
- Plastic and Reconstructive Surgery Global Open, 2026 · Dual-mode LinearZ case series
38 Korean adults enrolled; 32 completed 12-week follow-up. Single-arm case series without a sham control; hollow-prone faces were excluded. Longer-term durability remains uncertain.
- Cells, 2023 · HIFU, collagen and elastin in experimental models
Laboratory and animal research using LinearZ; it does not establish a person’s result, treatment interval or duration of benefit.
- US FDA · Non-invasive body contouring technologies, ultrasound section
General ultrasound safety context, not a LinearZ-specific approval or a facial treatment protocol.
- Sofwave · Official safety information
Sofwave-specific indications, precautions and adverse events; these are not interchangeable with LinearZ instructions.
- Sofwave · Ultrasound technology overview
Manufacturer overview describing mid-dermal ultrasound; it does not establish superiority over another device.
- Ultherapy · Official technology overview
Manufacturer information about real-time ultrasound imaging; this is a technical distinction, not a head-to-head outcome trial.
- Medical Lasers, 2025 · Two-depth versus three-depth LinearZ split-face study
22 Korean women; follow-up to 16 weeks. Between-protocol lifting differences were not statistically significant. Funded by Jeisys and a Korean health research grant; no Ultherapy arm.
- Jung et al., 2016 · Evaluator-blinded split-face comparison of two HIFU devices
20 Korean patients; abstract describes similar efficacy. Device names are not in the abstract available here. Do not identify it as a LinearZ–Ultherapy trial without verifying full methods.
- CLASSYS · ULTRAFORMER MPT
Official manufacturer identification. Ultraformer is a CLASSYS platform, distinct from Jeisys LinearZ.
- Jeisys Medical · ULTRAcel, LinearFirm and LinearZ device history
Manufacturer generation history; predecessor studies do not automatically establish outcomes for the current system.
Manufacturer descriptions, research and clinic practices describe different evidence. This clinic-review edition does not claim a clinical review endorsement.