By LIV Clinic · Medically reviewed by Dr. Narathai Vichienkalayarut, M.D. · Published October 16, 2026

They show up in photographs long before anyone notices them in the mirror — two small diagonal creases either side of the nose.

What are bunny lines and can Botox treat them? Bunny lines are the diagonal creases that appear on either side of the bridge of the nose when you scrunch, squint or smile strongly, caused by the nasalis muscle. Yes — a very small dose of botulinum toxin placed carefully in that muscle softens them, and it is a common add-on to frown-line treatment.

What bunny lines are

The nasalis muscle

Bunny lines — sometimes called scrunch lines — are the short diagonal creases that run across the upper sides of the nose. They are produced by the nasalis muscle pulling the nose upward and inward when you squint, sniff or smile broadly.

Why the name

The nose-scrunching movement that creates them resembles a rabbit twitching its nose, which is where the informal name comes from.

Why they appear

Expression habits

Some people naturally recruit the nasalis muscle when they smile or squint. In a bright, sunny climate, frequent squinting makes this more pronounced.

The compensation effect

Bunny lines sometimes become more obvious after frown-line treatment, because the frown muscles are softened and the nose area works slightly harder in strong expression. This is one of the most common reasons people first notice them.

How Botox treats bunny lines

A small, precise dose

Botulinum toxin temporarily blocks the nerve signals that make a muscle contract, as the Cleveland Clinic describes. Placed superficially in the nasalis, a few units per side are usually enough to soften the crease.

Why precision matters

The muscles that lift the upper lip sit immediately below. Product that diffuses too low can affect the smile or upper-lip movement, so this is a small-volume, shallow-placement treatment.

Treatment at a glance

Illustrative only; your doctor confirms dosing based on how strongly the muscle moves.

Who it suits, and who it does not

Worth considering if:

• You see diagonal nose creases in photographs when you smile
• You have noticed them more since having your frown lines treated
• You squint often in bright sunlight
• You are already having upper-face treatment and want a balanced result
• The creases are visible in expression rather than etched at rest

Less suitable

If the lines are deeply etched at rest, or if the appearance is mostly from sun damage and thin skin, a skin treatment plan addresses more than toxin will.

Possible side effects specific to this area

Upper-lip and smile effects

Because the lip elevators are close by, the main area-specific risk is a temporary change in how the upper lip moves or an asymmetric smile. Conservative dosing and shallow placement make this unlikely.

The usual injectable effects

Pinpoint redness, mild tenderness and occasional small bruising apply here as elsewhere. The MedlinePlus entry lists symptoms that should prompt medical attention.

Step-by-step: preparing for bunny line treatment

A short preparation sequence:

1. Photograph your face smiling broadly and squinting, in natural daylight.
2. Check whether the creases are visible when your face is completely relaxed.
3. Book a consultation and ask whether the nasalis is genuinely the cause.
4. Mention if you have had frown-line treatment, as compensation may be the trigger.
5. Agree a very conservative dose, given how close the lip muscles sit.
6. Avoid alcohol and blood-thinning supplements for 24–48 hours beforehand, where appropriate.
7. Review at about two weeks to check smile symmetry and decide on any top-up.

Bunny line treatment at LIV Clinic

Treated as part of the whole upper face

At LIV Clinic on Koh Samui and Koh Phangan, Dr. Narathai assesses how your nose, frown and eye muscles work together rather than treating a single crease in isolation.

Read next

See our Botox and wrinkle programme, explore dermal filler for volume-related nose and midface changes, or book a consultation.

Frequently asked questions

Safety and consultation

Bunny line Botox is a prescription medical treatment and, like any injectable, carries some risk — common temporary effects can include redness, swelling, bruising, mild headache or a short-lived heaviness, and less common reactions such as temporary eyelid or brow droop are possible. Results vary from person to person, and no specific outcome can be promised. This article is general information, not medical advice.

At LIV Clinic, every treatment begins with an in-person assessment by Dr. Narathai Vichienkalayarut, M.D., who reviews your skin, medical history and goals before recommending a personalized plan. Book a consultation to find out whether this treatment suits you.