Bunny Lines and Botox: Causes, Results and What the Evidence Shows
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Bunny lines are the small diagonal or vertical creases on the sides of the upper nose that appear when you scrunch your nose, smile or laugh. A 2025 anatomy study links them to the nasalis muscle. Botulinum toxin is the usual treatment, but in the largest case series only 40% of patients were satisfied after 1 round. Evidence: Limited.
This guide separates two things people mean by "bunny lines from Botox." One is Botox used for bunny lines. The other is bunny lines that seem to appear after Botox elsewhere on the face. If you have just been treated, our guide to skincare after Botox covers aftercare.
Key takeaways
- A 2025 ultrasound and cadaver study found a muscle-free zone, the "bunny triangle," under bunny lines, so injecting straight into the crease may miss the muscle (Ahn et al., 2025).
- In a 250-patient case series, 40% were satisfied 1 month after nasalis-only toxin, and 60% still had nose wrinkles that improved with extra injection points (Tamura et al., 2005).
- A 2022 review lists nasal "bunny" lines among the off-label uses of botulinum toxin A (Hanna et al., 2022).
- No study in our sources measures how long bunny line Botox lasts. Toxin in nearby nostril muscles had worn off close to baseline by 24 weeks (Wang et al., 2025).
- We found no studies of creams, peptides or "smoothers" on bunny lines.
What are bunny lines?
Bunny lines are wrinkles on the upper sides of the nose, just below the bridge, that form when the nose scrunches. A 2025 anatomy paper calls them "vertical and diagonal wrinkles attributed to contractions of the nasalis muscle" (Ahn et al., 2025).
Sources don't describe them identically. A 2015 review calls them "transverse nasal lines" (Erickson et al., 2015), and a 2005 case series uses the broader term "nasal wrinkles on the dorsum of the nose" (Tamura et al., 2005). The direction of the lines varies from person to person, which is one reason treatment plans differ.
Bunny lines are dynamic wrinkles, meaning they show with movement rather than at rest. We found no data on how common they are, or at what age, sex or skin type they show up most. Evidence: Limited.
What causes bunny lines?
The main driver is the nasalis, a thin muscle across the nose that pulls the skin when you scrunch. Neighboring muscles matter too: the procerus between the brows, the orbicularis oculi around the eye, and the levator labii superioris alaeque nasi (LLSAN), which lifts the upper lip and nostril.
The most detailed evidence comes from a 2025 study that used ultrasound in 13 adult volunteers (mean age 29.4 years) and dissected 39 cadavers (Ahn et al., 2025). The researchers consistently found a non-muscular area, which they named the "bunny triangle," between the borders of those 4 muscles. Its size and shape varied with the width of the procerus and nasalis. The authors say the surrounding muscles affect how the thin skin between the inner corner of the eye and the nasal bridge folds.
Injectors often add age, sun damage and genetics as causes. No study in our sources tests those, so treat them as expert opinion. Evidence: Limited (1 anatomy study; causes beyond muscle anatomy untested).
Bunny lines from Botox: why can they appear after frown-line treatment?
Injectors' usual explanation is compensation: when frown or crow's-feet muscles are relaxed, untreated muscles on the nose may work harder, so bunny lines become more noticeable. No study has tested this directly, so it is expert opinion, not established fact. For lines higher up, see our forehead wrinkles guide.
It's a common reader question. Someone has their frown lines treated, then notices their upper nose scrunching and creasing more, and wants to know how to stop it without giving up frown-line treatment. Clinicians answering that kind of question usually suggest a small extra treatment on the nose.
Two sources give indirect support. A 2025 consensus review, which rates its own level of evidence as 5 (expert opinion), concluded that "anatomical variations, generic on-label injection patterns, and inadvertent muscle recruitment contribute to suboptimal outcomes" and recommended "simultaneous treatment of linked or antagonistic muscles" (Goodman et al., 2025). In the 250-patient series, 30% of patients had leftover wrinkles at the nasal root and between the eyes after nasalis-only treatment, which shows how the muscles of the nose and brow overlap (Tamura et al., 2005). Neither study looked at lines appearing after Botox elsewhere. Evidence: expert opinion.
Does Botox work for bunny lines?
Botox often improves bunny lines, but 1 round of standard nasalis injections doesn't fully clear them for most people in the only outcome study we found. The evidence is a single uncontrolled case series, with no randomized trial.
That series treated 250 patients with nasal wrinkles between 1997 and 2004 (Tamura et al., 2005). The study injected 3 units of botulinum toxin type A bilaterally into the nasalis and checked patients at 1 month. The abstract notes that 2 to 5 units have commonly been used, and it doesn't report funding. These figures describe what the study did; they're not dosing advice.
Show data table
| Outcome at 1 month | Patients (%) |
|---|---|
| Satisfied after first injections | 40% |
| Persistent wrinkles at nasal root | 30% |
| Wrinkles at nasal root and between eyes | 30% |
The 60% with remaining wrinkles then received injections at extra points chosen for each person's anatomy. The authors report "excellent resolution of the rhytids without complications," but give no figure for how many patients that covered. With no control group or blinded rating, the study can't show how much of the improvement came from toxin alone.
The rest of the evidence is expert opinion. Consensus panels of 9 and 10 Italian specialists include bunny lines in their onabotulinumtoxinA guidance (Bertossi et al., 2018; Signorini et al., 2022). An international board on Alluzience, a ready-to-use abobotulinumtoxinA made by Ipsen and Galderma, does too (Ascher et al., 2024); funding isn't stated in the abstract. A 2015 review says satisfaction with midface and eye-area toxin "tends to be very high," a general statement, not bunny-line data (Erickson et al., 2015).
On approval status, a 2022 review lists nasal "bunny" lines among the off-label uses of botulinum toxin A (Hanna et al., 2022). Ask your injector about the product they plan to use. Evidence: Limited.
| Tamura et al., Dermatol Surg, 2005 | 250 | 1-month follow-up | 3 U injected bilaterally into the nasalis | 40% satisfied; 60% had remaining nasal wrinkles |
| Ahn et al., Clin Anat, 2025 | 13 volunteers + 39 cadavers | Single assessment | None (anatomy study) | Muscle-free 'bunny triangle' under bunny lines |
| Wang et al., Aesthetic Plast Surg, 2025 | 52 recruited, 32 completed | 24 weeks | Nasal dilator muscles (dose not in abstract) | Nostril area 89.42 to 72.50 mm2 at 4 weeks; near baseline by 24 weeks |
| Alimohammadi et al., Acta Derm Venereol, 2014 | 16 women | 24 weeks | 3 dose groups vs placebo (glabella) | Paralysis began from 2 weeks; not fully reversed at 24 weeks at high dose |
| Yi et al., J Cosmet Dermatol, 2025 | 32 | Cross-sectional | None (anatomy study) | Distinct muscles in the nasal ala moving at diverse depths |
Tamura et al., Dermatol Surg, 2005
Result: 40% satisfied; 60% had remaining nasal wrinkles
Uncontrolled case series, 1997 to 2004. Extra anatomy-based injection points gave 'excellent resolution' without complications, per the authors. Funding not reported. Evidence: Limited.
Ahn et al., Clin Anat, 2025
Result: Muscle-free 'bunny triangle' under bunny lines
Ultrasound and dissection. In-crease injection 'is likely to target connective tissue rather than a muscle.' No treatment outcomes. Evidence: Limited.
Wang et al., Aesthetic Plast Surg, 2025
Result: Nostril area 89.42 to 72.50 mm2 at 4 weeks; near baseline by 24 weeks
Prospective study of nostril overexposure, not bunny lines. Authors declared no conflicts. Evidence: Early / preliminary.
Alimohammadi et al., Acta Derm Venereol, 2014
Result: Paralysis began from 2 weeks; not fully reversed at 24 weeks at high dose
Double-blind placebo-controlled RCT of frown-line treatment, not bunny lines. Evidence: Early / preliminary.
Yi et al., J Cosmet Dermatol, 2025
Result: Distinct muscles in the nasal ala moving at diverse depths
Ultrasound of 15 women and 17 men aged 20 to 65. No treatment outcome. No conflicts declared. Evidence: Early / preliminary.
No randomized trial of toxin for bunny lines exists in our sources.
Where is bunny line Botox injected, and why is that changing?
Bunny lines have traditionally been treated by injecting into or just around the visible creases below the nasal bridge. Newer anatomy work suggests targeting the edges of the surrounding muscles instead, though no trial has compared the two approaches.
The 2025 bunny-triangle study concluded that "conventional BoNT injection into bunny line wrinkles is likely to target connective tissue rather than a muscle, potentially producing suboptimal results," and that injection points "probably need to target the borders" of the procerus, nasalis, orbicularis oculi and LLSAN (Ahn et al., 2025). A 2022 anatomical review from overlapping authors names the nasalis, procerus and LLSAN as the optimal sites and says the injection point "may be more precisely defined" (Yi et al., 2022); it declared no conflicts.
Some clinicians now use ultrasound to see the muscles before injecting. A 2023 narrative review discusses the merits of ultrasound-assisted injection and lists nasal rhytides among toxin indications (Hong, 2023). That fits the 2025 consensus view that injection plans should follow each patient's anatomy rather than a generic map (Goodman et al., 2025). Evidence: expert opinion; anatomy only.
How fast does bunny line Botox work and how long does it last?
No study in our sources measures onset or duration for bunny lines specifically. The closest data come from nearby areas and should be read as indirect.
What studies of nearby areas show (indirect, not bunny lines)
- From 2 weeksMuscle paralysis measurable
In a 16-woman RCT of frown-line toxin, paralysis measured by EMG began from 2 weeks (Alimohammadi et al., 2014).
- 3–14 daysWindow for rare eyelid droop
A review puts the mean onset of toxin-related eyelid ptosis at 3 to 14 days, based on brow-area injections (Nestor et al., 2021).
- 4 weeks / 1 monthTypical check-in point in studies
The bunny line case series assessed results at 1 month (Tamura et al., 2005); a nostril study found its clearest effect at 4 weeks (Wang et al., 2025).
- 24 weeksEffect fading
Nostril measurements 'approached baseline levels' at 24 weeks (Wang). In the frown-line RCT, paralysis was not entirely reversed at 24 weeks in the high-dose group (Alimohammadi).
The nostril study recruited 52 patients and followed 32 for 24 weeks after toxin in the nasal dilator muscles (Wang et al., 2025). Those are different muscles from the ones behind bunny lines, but they're close by. In the frown-line RCT, the effect also depended on dose (Alimohammadi et al., 2014).
Any re-treatment interval a clinic quotes for bunny lines is clinic convention, not a bunny-line study result. Evidence: Early / preliminary (indirect).
What can go wrong with bunny lines Botox?
The most likely "gone wrong" outcome in the evidence is a weaker or incomplete result, not a complication. Rarer problems come from toxin reaching a muscle it wasn't meant for.
Incomplete smoothing. In-crease injection may land in connective tissue rather than muscle (Ahn et al., 2025), and 60% of patients in the case series had leftover wrinkles after nasalis-only treatment (Tamura et al., 2005). Uneven or unnatural results are linked more broadly to generic injection patterns and unwanted muscle recruitment (Goodman et al., 2025).
Eyelid droop. A 2021 review describes toxin-related eyelid ptosis as rare and says it "more frequently occurs among inexperienced practitioners" (Nestor et al., 2021). Mean onset is 3 to 14 days after injection, and it eventually resolves as the toxin wears off. That review focused on injections near the brow, not the nose, and its authors declared no conflicts.
Lip or lower-lid effects. Some injectors warn that toxin placed low or wide on the nose could affect the upper lip or lower eyelid. No study in our sources measures how often that happens, so treat it as expert opinion. A 2015 review covers managing complications of bunny-line injection without giving rates (Erickson et al., 2015). Contact your injector, or seek urgent care, if you notice drooping, vision changes or trouble swallowing. Evidence: expert opinion.
Bunny lines before and after: what is a realistic result?
A realistic expectation is visible softening after the first session, with a fair chance that some lines remain and need a follow-up visit. In the 250-patient series, 4 in 10 people were satisfied after the first round, and most of the rest had lines left at the nasal root or between the eyes (Tamura et al., 2005).
Before-and-after photos from clinics show selected cases, often with different lighting, angles and expressions. Ask whether the "after" photo shows the face scrunching, since bunny lines are dynamic and may not show in a relaxed face. The study above judged results at 1 month, so a check-in around that point matches how the only outcome data were collected. Evidence: Limited.
Can a bunny line smoother, cream or peptide help?
We found no studies testing any cream, serum, patch or "bunny line smoother" on bunny lines. That includes peptides marketed as "Botox-like."
Neurotransmitter-inhibiting peptides such as Argireline (acetyl hexapeptide-8), SNAP-8 (acetyl octapeptide-3) and SYN-AKE are applied to the skin surface, while bunny lines come from muscle movement underneath. Our guides to what Argireline does, SNAP-8 peptide and Syn-Ake peptide cover what each has and hasn't shown on other areas. For a broader ranking, see our peptide ingredients guide and what peptides do for your skin.
Any of these is untested on bunny lines. We also found no filler studies for bunny lines; a consensus guide warns that filler near the nose carries "risk of serious complications, including blindness and necrosis" (de Maio et al., 2017). Our dermal fillers guide covers filler more generally. Evidence: no studies.
Is "bunny nose Botox" the same as treating bunny lines?
Not always. "Bunny nose Botox" can mean treating bunny lines, but people also use it for toxin aimed at flaring nostrils, a drooping tip or overall nose shape, which target different muscles.
| Feature | Bunny lines | Nostrils | tip and shape |
|---|---|---|---|
| Target | Nasalis and neighboring muscle borders | Nasal dilator muscles, nasal ala, tip | |
| Goal | Soften creases when scrunching | Narrow nostril flare, lift tip, reshape | |
| Best data | Case series, n=250 (Tamura) | Prospective, 32 completed (Wang); 85 patients, combined methods (Ziade) | |
| Anatomy work | Bunny triangle (Ahn) | Nasal ala ultrasound, n=32 (Yi) |
Bottom line: Ask your injector which muscles they plan to treat; the terms overlap online.
A 2017 consensus guide lists toxin both for bunny lines and for elevating the nasal tip (de Maio et al., 2017). A 2025 prospective study of 85 nonsurgical nose-reshaping patients split them into 3 groups: 63 had filler plus toxin, 9 had threads plus toxin, and 13 had threads, filler and toxin (Ziade et al., 2025). The triple combination had the highest satisfaction scores at 1 month and 1 year, adverse effects resolved by 1 week, and the authors declared no conflicts.
Toxin in the nose also has a medical use. In a retrospective review of 99 patients with facial synkinesis (involuntary linked facial movement), 23 (23.5%) reported new nasal obstruction, and 74% of those had relief at 4 weeks after toxin in the perinasal muscles (Boyce et al., 2025). That is functional treatment, not cosmetic. Evidence: Limited.
Where the evidence stops
- No randomized trial of toxin for bunny lines. The best outcome data is 1 uncontrolled case series from 2005.
- No duration study for bunny lines; timing figures come from nostril and frown-line studies.
- No study of bunny lines appearing after Botox; the compensation explanation is expert opinion.
- Border vs in-crease injection has not been compared in patients; the bunny-triangle finding is anatomy only.
- No studies of creams, peptides, patches, smoothers or filler for bunny lines.
- Lip or lower-lid side effects from nose injections have no rates in our sources.
- No data on prevalence, age of onset, sex or skin type. Pregnancy, breastfeeding and drug interactions aren't covered either; ask a clinician.
FAQ
What are bunny lines?
Bunny lines are the small diagonal or vertical creases on the sides of the upper nose that show when you scrunch your nose, smile or laugh. A 2025 anatomy study attributes them to contraction of the nasalis muscle and describes how neighboring muscles shape the thin skin in that area.
Why did I get bunny lines after Botox?
Injectors commonly explain that when frown or eye muscles are relaxed, untreated nose muscles may work harder and make bunny lines more visible. No study has tested this directly, so it is expert opinion. A 2025 consensus review links generic injection patterns and inadvertent muscle recruitment to suboptimal toxin results in general.
Does Botox get rid of bunny lines?
It often helps, but one round may not clear them all. In a case series of 250 patients, 40% were satisfied 1 month after nasalis-only injections, and the 60% with remaining wrinkles improved after injections at extra points chosen for their anatomy.
Is Botox for bunny lines an approved use?
A 2022 review lists nasal bunny lines among the off-label uses of botulinum toxin A. Expert consensus panels still include bunny lines in their injection guidance. Ask your injector about the specific product and plan they use.
How long does bunny line Botox last?
No study has measured this for bunny lines. In a small study of toxin in the nearby nostril muscles, measurements approached baseline by 24 weeks. Any re-treatment interval a clinic quotes for bunny lines is clinic convention.
What can go wrong with bunny line Botox?
Anatomy research suggests injecting straight into the crease may hit connective tissue instead of muscle, giving a weaker result. Toxin spread in the face can rarely cause a droopy eyelid, which a review says usually starts 3 to 14 days after injection and wears off; that review focused on the brow area, not the nose.
Can a cream, peptide or bunny line smoother fix bunny lines?
We found no studies testing any cream, peptide, patch or smoother on bunny lines. Peptides marketed as Botox-like, such as Argireline and SNAP-8, have not been tested on this area.
Can filler treat bunny lines instead?
We found no filler studies for bunny lines. A consensus guide warns that filler near the nose carries a risk of serious complications, including blindness and necrosis, and advises injectors to get specific training for the area.
References
- Ahn H, et al. Anatomical etiology of bunny lines based on cadaveric dissection and ultrasonographic evaluation. Clin Anat. 2025. Ultrasound in 13 volunteers + dissection of 39 cadavers; funding not reported in abstract. https://pubmed.ncbi.nlm.nih.gov/39711041/
- Tamura BM, et al. Treatment of nasal wrinkles with botulinum toxin. Dermatol Surg. 2005. Case series, n=250, 1-month follow-up; funding not reported. https://pubmed.ncbi.nlm.nih.gov/15841625/
- Yi KH, et al. Novel Anatomical Guidelines on Botulinum Neurotoxin Injection for Wrinkles in the Nose Region. Toxins (Basel). 2022. Anatomical review; non-US government support; no conflicts declared. https://pubmed.ncbi.nlm.nih.gov/35622589/
- Erickson BP, et al. The role of neurotoxins in the periorbital and midfacial areas. Facial Plast Surg Clin North Am. 2015. Review. https://pubmed.ncbi.nlm.nih.gov/25921574/
- Bertossi D, et al. Italian consensus report on the aesthetic use of onabotulinum toxin A. J Cosmet Dermatol. 2018. Consensus, panel of 9. https://pubmed.ncbi.nlm.nih.gov/30091253/
- Signorini M, et al. OnabotulinumtoxinA from lines to facial reshaping: A new Italian consensus report. J Cosmet Dermatol. 2022. Consensus, panel of 10. https://pubmed.ncbi.nlm.nih.gov/35060310/
- Ascher B, et al. International Consensus Recommendations on the Aesthetic Usage of Ready-to-Use AbobotulinumtoxinA (Alluzience). Aesthet Surg J. 2024. Consensus on an Ipsen/Galderma product; funding not stated in abstract. https://pubmed.ncbi.nlm.nih.gov/37490767/
- de Maio M, et al. Facial Assessment and Injection Guide for Botulinum Toxin and Injectable Hyaluronic Acid Fillers: Focus on the Midface. Plast Reconstr Surg. 2017. Consensus guide. https://pubmed.ncbi.nlm.nih.gov/28953721/
- Hanna E, et al. Role of botulinum toxin A in improving facial erythema and skin quality. Arch Dermatol Res. 2022. Review. https://pubmed.ncbi.nlm.nih.gov/34519860/
- Hong SO. Cosmetic Treatment Using Botulinum Toxin in the Oral and Maxillofacial Area: A Narrative Review of Esthetic Techniques. Toxins (Basel). 2023. Narrative review; no conflicts declared. https://pubmed.ncbi.nlm.nih.gov/36828397/
- Goodman GJ, et al. Botulinum Toxin: Surely, We Can Do Better? Optimizing Results Beyond On-Label Techniques and Teaching. Aesthet Surg J Open Forum. 2025. Consensus review, Level of Evidence 5. https://pubmed.ncbi.nlm.nih.gov/40585019/
- Nestor MS, et al. Botulinum toxin-induced blepharoptosis: Anatomy, etiology, prevention, and therapeutic options. J Cosmet Dermatol. 2021. Literature review + dissection; no conflicts declared. https://pubmed.ncbi.nlm.nih.gov/34378298/
- Wang X, et al. Botulinum Toxin Type A for Nostril Overexposure: A Prospective Clinical Study Using 3D Scanning. Aesthetic Plast Surg. 2025. Prospective, 52 recruited, 32 completed 24 weeks; no conflicts declared. https://pubmed.ncbi.nlm.nih.gov/40301199/
- Alimohammadi M, et al. Correlation of botulinum toxin dose with neurophysiological parameters of efficacy and safety in the glabellar muscles: a double-blind, placebo-controlled, randomized study. Acta Derm Venereol. 2014. Double-blind placebo-controlled RCT, n=16, 24 weeks. https://pubmed.ncbi.nlm.nih.gov/23975053/
- Yi KH, et al. Sonoanatomy of the Nasal Ala for Botulinum Neurotoxin Injection. J Cosmet Dermatol. 2025. Cross-sectional ultrasound, n=32; no conflicts declared. https://pubmed.ncbi.nlm.nih.gov/40152086/
- Ziade G, et al. Nasal Reshaping Using Barbed Threads Combined With Hyaluronic Acid Filler and Botulinum Toxin A. J Cosmet Dermatol. 2025. Prospective, n=85, 1-year follow-up; no conflicts declared. https://pubmed.ncbi.nlm.nih.gov/39936459/
- Boyce C, et al. Role of Perinasal Musculature in Ipsilateral Nasal Obstruction During Synkinesis Progression. Facial Plast Surg Aesthet Med. 2025. Retrospective, n=99, 4-week assessment; non-US government support. https://pubmed.ncbi.nlm.nih.gov/40876003/
Disclosure: This article is for general information only. It is not medical advice. Peptide Skincare has no affiliate links in this article and received no payment from any manufacturer mentioned. Botulinum toxin injections are a medical procedure; see a qualified, licensed injector, and seek care for drooping, vision changes or trouble swallowing after any injection.