Fillers

Lip Filler (Horizontal Widening) in Seoul: Planning Your Visit

A planning guide for visitors considering lip filler (horizontal widening) at RESUM in Gangnam: time needed, the first days of swelling and the limits of the treatment.

Plan a consultation

Published: 2026-10-15

Updated: 2026-10-15

At a glance

The injection takes 10-20 minutes and daily activities can resume right after.
It lengthens the line at the corners of the mouth and does not plump the lips.
No more than 1ml is used in 1 session, including when lip volume is added.

How horizontal widening differs from adding lip volume

Lip filler (horizontal widening) is a hyaluronic acid filler treatment that makes the mouth look wider instead of fuller. Small amounts are placed from the corners of the mouth along the lip border (vermilion border), so the side line is lengthened while the height of the lips stays much the same.

It is planned as a proportion treatment. At RESUM Plastic Surgery Clinic in Gangnam, Seoul, Dr. Jin-Young Kim compares the width of the mouth with the width of the face, the upper lip with the lower lip, and the length of the philtrum, using photos of your face during the consultation. The product and the injection points are not the ones used for a standard lip filler.

How long does the appointment take?

The injection takes 10-20 minutes. Add time for the consultation, the photo review and the topical anaesthetic. Lips swell more visibly than other areas, so if you can choose, place the appointment early in your stay and keep the following 2-3 days free of important plans.

Treatment time	10-20 minutes
Anaesthesia	Topical anaesthesia; local anaesthesia in some cases
Back to daily activities	Right after the treatment
How long it lasts	About 6-12 months

When horizontal widening is not the answer

Horizontal widening changes little by itself when the mouth looks small because of a long philtrum or the proportions of the chin. In that case the doctor may suggest another treatment, a combination with Botox, or no treatment at all. It is also not the treatment for fuller lips. Volume is a separate plan with a product of a different viscosity.

Photo gallery

Purpose & suitability

Your mouth looks narrow for the width of your face.

The corners of your mouth turn down, so your resting face looks low in mood.

You like the fullness of your lips and only want the horizontal line extended.

The upper and lower lips look uneven in width.

You want width first and volume later, in stages.

Treatment process

Consultation. Lip proportions, the line at the mouth corners, philtrum length and expression lines are checked, and photos of your face are reviewed with you.
Plan. The doctor sets how far to widen for your facial width, how much to use and how deep to place it at the lip border.
Numbing and injection. After topical or local anaesthesia, small amounts are placed slowly along the mouth corner line, with a cannula preferred.
Before you leave. The horizontal balance and the shape of the Cupid's bow are checked, and you are told when an addition could be considered.

Time & recovery

Swelling and tenderness are most noticeable in the first 1-2 days, and more so on the lips than elsewhere because the lips move constantly.

Keep the first 2-3 days flexible. Bruising and tenderness usually calm down within a few days.

The new line is visible straight away and settles at around 1 week. Judge the final shape once the swelling has gone.

Limitations & precautions

The treatment is not performed during pregnancy. If you have had cold sores (herpes simplex), say so beforehand so that preventive medication can be decided.

Nodules, asymmetry and hypersensitivity reactions have been reported in rare cases. The amount is spread in small portions so that the Cupid's bow keeps its shape.

Vascular complications are reported very rarely. Branches of the superior and inferior labial arteries run around the mouth corners, so the depth is controlled, the injection is slow and a dissolving enzyme (hyaluronidase) is kept ready.

Results vary between individuals, and a specialist consultation is required before treatment.

Frequently asked questions

Can I fit this treatment into a short stay in Seoul?

Yes. The injection takes 10-20 minutes and daily activities can resume right after. Lip swelling tends to stand out for the first 1-2 days, so keeping 2-3 days free of important plans is advisable.

How is numbing handled for the lips?

Topical anaesthesia is applied before the lip injection, and local anaesthesia can be used. Tenderness is common for the first 1-2 days and tends to be felt more on the lips than in other areas.

Will it make my lips look bigger?

No, that is not the aim. Horizontal widening extends the line at the corners of the mouth and along the lip border without adding height to the lips, and the amount is controlled so that the lips do not look pushed upward.

Can I add lip volume or Botox at the same visit?

Yes, both can be planned. When volume is also wanted, a product of a different viscosity is used for each part and the total stays within 1ml for 1 session, with the horizontal line set first and volume added in stages. Botox is discussed when the corners of the mouth angle downward.

How long does the widening last?

Lip filler (horizontal widening) lasts about 6-12 months. The line is visible right after treatment and settles at around 1 week, so the result can be judged soon after you return home.