What are bunny lines and which muscle causes them?
Bunny lines are slanting lines that run down and outward on both sides of the nose root and upper nose bridge when you scrunch your nose. They form mainly through contraction of the part of the nasalis muscle that crosses the nose bridge; the procerus muscle between the brows can also contribute to the horizontal lines at the nose root.
The nasalis is a thin muscle that starts at the upper part of the nostrils, runs over the nose bridge and joins its partner on the other side. When its transverse part contracts, the skin of the upper nose gathers upward and inward and slanting lines appear on both sides of the nose root. The look resembles a rabbit twitching its nose, which is why they are called “bunny lines”. In most people the lines are noticed while laughing, squinting in the sun or grimacing while talking. The procerus muscle between the brows can produce horizontal lines between the two eyes at the nose root. These horizontal lines are usually handled together with treatment between the brows, while the slanting lines at the sides of the nose root need separate points on the nasalis.
How pronounced bunny lines are varies greatly. In people who use their expressions heavily and scrunch the nose noticeably when laughing, they can be seen at a younger age. Thin skin, sun damage and reduced elasticity with age also make the lines look more marked. At first the lines appear only with movement and disappear at rest; over the years, particularly in thin skin, faint traces can remain at rest too. Botox targets the movement-related component of these lines, so whether the line is dynamic or already set is first distinguished at the consultation. This distinction also shapes what can be expected: lines caused by movement often soften noticeably, while set traces may change less.
Why can bunny lines become more noticeable after Botox between the brows?
After Botox between the brows and at the corners of the eyes, bunny lines can look more marked in some people. This is thought to be linked to the nasalis being used more to create expression in place of the relaxed muscles. It reflects a change in the balance of facial muscles and can often be anticipated at the planning stage.
A facial expression is formed not by one muscle but by many working together. When the muscles that frown and squint are relaxed with Botox, some people unknowingly start to create a similar expression by scrunching the nose. Bunny lines that previously attracted no attention can then stand out once the area between the brows has softened. This change is usually noticed days or weeks after treatment, as the face adjusts to the new muscle balance. A similar interaction can also be seen after crow’s-feet treatment, in lines appearing under the eye and on the upper cheek. How relaxing one area may affect its neighbours is therefore thought through together at the planning stage.
That is why, when Botox between the brows is planned, it is also checked whether lines form when you scrunch your nose. In people with marked bunny lines, this area can be added to the plan in the same session with a measured dose, so that the movement of the face remains more natural. If the lines are only noticed at the review, a small additional treatment can be considered at that stage. The movement of the nose does not need to be stopped completely; the aim is to soften marked scrunching while keeping expression lively. Which areas to treat together is decided at an examination with the face in motion. If you have had Botox between the brows before and noticed more scrunching of the nose afterwards, mentioning it helps planning.
How is Botox for bunny lines done and how is the dose decided?
Botox for bunny lines is given as small doses over the nasalis muscle on both sides of the nose root, often as one or several points on each side. The dose in this area is generally lower than for the forehead or between the brows; the amount is set by muscle strength, where the line sits and the product used.
Before treatment you are asked to scrunch your nose and smile, and where the lines begin, the direction they run and any differences between the two sides are identified. Injection points are chosen at the sides of the upper nose bridge, over the part of the muscle that forms the lines. This area is close to the muscles that lift the upper lip and the nostril wing. If points are placed too low or too far out, the toxin can reach those muscles; point selection and dose are therefore made carefully according to the anatomy of the area. Treatment usually takes a few minutes. Because the skin is thin, a brief stinging is felt, and most people return to daily life the same day. In sensitive people, brief cold application may be used before treatment.
The dose is adjusted to how marked the lines are and how strongly the nose is scrunched. Because unit values of products are not equivalent, comparing the units given for this area with another person or another product can be misleading. For a first treatment a cautious dose is generally preferred, and the result is assessed at the review at about two weeks, when the effect has fully set in. As elsewhere on the face, the effect starts within a few days and lasts around 3–4 months for most people; with small doses it may fade earlier. In the first hours after treatment you are advised not to press or rub the area. The purpose of this advice is to reduce the chance of the toxin reaching neighbouring muscles beyond the target.
What are the side effects of Botox for bunny lines?
The common side effects of Botox for bunny lines are redness, tenderness and small bruises at the injection points. Rarely, if the toxin reaches the muscles that lift the upper lip, there can be a slight droop of the upper lip, asymmetry when smiling or a different expression around the nose. These effects are usually temporary but can last a few weeks.
Because there are superficial blood vessels at the sides of the nose bridge, small bruises can occur here; they generally change colour and fade within a few days. Slight swelling and tenderness at the needle sites usually pass quickly too. If you take blood thinners, aspirin or some supplements, the chance of bruising may be higher; do not stop these on your own, and mention them at the consultation. Botox is not a filler; its risk profile differs from the blockage of blood vessels discussed with filler around the nose. Even so, like any injection, it requires careful technique and suitable conditions. If a bruise occurs, brief cold application on the first day may give relief; you can ask your doctor how to do this.
The more important rare side effect is spread of the toxin to surrounding muscles. If the muscles that lift the upper lip and the nostril wing are affected, one side of the upper lip may rise less when you smile, or the lip may look slightly lengthened. This effect is usually temporary; but because no medicine quickly reverses the effect of Botox, it is expected to resolve by itself over weeks. If you notice a marked change in your smile, it is important to tell your doctor. Symptoms such as difficulty swallowing, speaking or breathing are very rare but need urgent medical assessment, and you should seek care at a health facility without delay. Possible side effects and the signs to watch for are explained to you before treatment.
Who is Botox for bunny lines not suitable for, and what does it not change?
Botox for bunny lines is not given, or is postponed, in pregnancy and breastfeeding, neuromuscular conditions, infection at the site and hypersensitivity to the ingredients. Botox does not change the shape of the nose, the height of the nose root or a hump on the bridge; it does not remove fine lines from sun damage or established lines seen at rest on its own.
The medical suitability rules are the same as for other Botox treatments. Treatment is not given during pregnancy and breastfeeding, or in conditions affecting nerve-to-muscle transmission such as myasthenia gravis or Lambert-Eaton syndrome. Some antibiotics and other medicines that affect nerve-to-muscle transmission may change the assessment. If there is active acne, a cold sore or infection around the nose, it must heal first. If you have recently had nose surgery, timing is decided by considering the healing of the area and your surgeon’s advice. If you noticed a change in your smile after a previous Botox treatment, be sure to mention it, as it guides point selection. Your medicines, supplements and earlier treatments such as filler around the nose are also reviewed in detail. Where expectations do not match what Botox can achieve, treatment may not be recommended.
Knowing the limits of Botox for bunny lines makes it easier to set the right expectation. Botox does not hide a hump on the bridge, raise the nose root or change the width of the nose; contour changes of this kind are approached with different methods and a separate assessment. For thin skin and lines from sun damage that are independent of movement, treatments aimed at skin quality and regular sun protection may be part of the plan. The nose area needs particular care with filler because of its blood supply; filler is therefore generally not the first option for fine lines around the nose. Which method is needed is decided at the consultation. If you have expectations about the shape of your nose, the extent to which they can be met without surgery is discussed separately.
Frequently asked questions
Is Botox to lift the nose tip the same as Botox for bunny lines?
No, they are different treatments. Botox for bunny lines targets the nasalis muscle beside the nose root and softens lines formed when you scrunch your nose. The nose-tip treatment targets a small muscle at the base of the nose that pulls the tip down when you smile; its effect is limited and it does not suit everyone. Botox does not change the structural shape of the nose.
Do I need Botox if my bunny lines only show when I laugh?
It is not needed. Bunny lines that appear only when you laugh or scrunch your nose are a natural part of facial expression and are not a condition that requires treatment. If they bother you, or became more marked after Botox between the brows, Botox can be considered as an option. The decision is made together, according to your preference and the expectations discussed at the consultation.
Will Botox for bunny lines stop me from scrunching my nose completely?
Usually not; the aim is not to stop the movement completely but to soften marked scrunching. Because low doses are used in the nose area, you can generally still move your nose a little. A higher dose may reduce movement further, but it also raises the chance of spread to neighbouring muscles and a change in your smile. The dose is set with that balance in mind.
How long does Botox for bunny lines last?
The effect of Botox for bunny lines usually starts within 2–5 days, settles at around two weeks and lasts around 3–4 months for most people. Because the doses in this area are small, the effect may fade earlier in some people. Duration varies with muscle strength, expression habits and personal features; the timing of a repeat is planned by how the lines return.
Can I have Botox for bunny lines if I have had a nose job?
Having had nose surgery is not in itself a barrier to Botox for bunny lines; timing, however, is set by how the area has healed. Because swelling and tenderness can persist in the tissues after surgery, your surgeon’s advice is also taken into account. Sharing the date and extent of the surgery at the consultation makes point selection and safe planning easier.
Can I wear glasses after Botox for bunny lines?
You can usually wear them. Because nose pads can sit close to the injection points, avoid pressing on those points in the first hours and avoid taking the glasses on and off in a way that rubs the area. A lighter pair on the first day may be more comfortable. Your doctor gives advice specific to you.
Can Botox for bunny lines and nose filler be done on the same day?
In some cases they can be planned in the same session, but the two treatments have different purposes and are assessed separately. Nose filler needs particular care because of the blood vessels. Splitting treatments over separate days may be preferred, because doing both on the same day can increase swelling and bruising and make it harder to tell which treatment caused a side effect.
Sources (2)
- Yi et al., Toxins (Basel): Novel Anatomical Guidelines on Botulinum Neurotoxin Injection for Wrinkles in the Nose Region (2022)
- International Botulinum toxin Advisory board (Ascher et al., Aesthet Surg J): International Consensus Recommendations on the Aesthetic Usage of Ready-to-Use AbobotulinumtoxinA (Alluzience) (2024)
This content is for general information and does not replace a personal medical assessment.