Smile lines can describe three different concerns. A crease from the nose to the mouth corner is a nasolabial fold, which usually responds to filler rather than Botox. Downturned mouth corners or fine lines around the lips may respond to small, carefully placed Botox doses. The right treatment starts with identifying the line.
“Smile lines” is a casual description, not an anatomical diagnosis. The answer to whether Botox for smile lines works depends on which pattern you mean.
| The Line | What Usually Causes It | What May Soften It |
|---|---|---|
| Nasolabial fold: A crease from the side of the nose to the corner of the mouth | Midface volume loss, skin laxity, and changes in the cheek fat pads can make this structural crease more prominent. | Filler in the cheek, the fold, or both, depending on the assessment. |
| Marionette lines or downturned mouth corners: Lines extending from the mouth corners toward the chin | Downward muscle pull, tissue changes, and lost volume. | Botox for excess muscle pull, filler for lost volume, or a staged combination. |
| Perioral or lipstick lines: Fine vertical lines on or around the lips | Repeated muscle movement, thinning skin, and other age-related changes. | Very small toxin doses for movement-related lines, sometimes with filler or skin treatments. |
Most people searching for Botox on laugh lines are looking at the first row while asking about a treatment used more often for the second or third. That distinction matters because relaxing a muscle cannot replace structural support or lost volume. Cleveland Clinic also notes that nasolabial folds are normal facial features that may become more prominent over time.
For marionette lines, Botox can reduce active downward pull, while filler can replace volume beneath a visible crease. When both contribute, a provider may stage the treatments.
Botox at InjectCo temporarily reduces activity in an injected muscle. Around the lower face, one possible target is the depressor anguli oris (DAO), a small muscle that pulls the mouth corner downward. Carefully relaxing it may soften an overactive downward pull, but it does not fill a marionette crease.
Small amounts may also be used in the orbicularis oris, the circular muscle around the lips, when repeated movement contributes to fine perioral lines. Botox on smile lines caused mainly by movement can help the line look softer while the toxin is active. It cannot replace volume or correct skin laxity.
In a narrow group of patients, conservative toxin placement may soften movement near the upper part of a fold. That does not make Botox a standard treatment for the nasolabial fold itself.
Treatment around the mouth is off-label. The current Botox Cosmetic prescribing information lists glabellar lines, lateral canthal lines, forehead lines, and platysma bands as approved cosmetic indications. It does not list perioral lines, the DAO, marionette lines, or nasolabial folds.
Published lower-face guidance commonly uses only two to four Botox units per side for the DAO. Perioral plans may total about five to seven units divided among several small sites. These are reference ranges, not personal dosing instructions. The product, anatomy, muscle strength, and treatment goal all affect the plan, and units from different toxin products are not interchangeable. Botox at InjectCo is $12 per unit, or $9 per unit for members.
Results from botulinum toxin generally last about three to four months, although individual results vary.
The muscles around the mouth are small, close together, and responsible for detailed movements. They help you smile, speak clearly, purse your lips, and keep liquids in your mouth. A small amount of toxin reaching the wrong muscle can therefore cause a noticeable functional change.
Possible lower-face effects include:
These effects can occur when the toxin spreads into a neighboring muscle or when the dose is too strong for the patient’s anatomy. Published guidance on perioral rejuvenation specifically warns about speech changes, trouble using a straw, drooling, lip flattening, and smile asymmetry.
That is why lower-face dosing is usually measured in only a few units and why the injector must assess the face both at rest and in motion. The goal is to reduce a specific pull without weakening the movements you need for speech, eating, and expression.
Local weakness is temporary and generally improves as the toxin wears off, but it can last for weeks or months. It should not be dismissed as a minor inconvenience. A careful assessment by our nurse injectors helps determine whether the possible benefit justifies that risk for your anatomy.
For the nasolabial fold itself, dermal filler is usually the more appropriate injectable treatment. Botox relaxes muscle activity. Filler adds support where volume has shifted or been lost, which better matches the structure of a true fold.
Placement does not always begin inside the crease. In some faces, restoring support higher in the midface with cheek filler can soften the fold because the nasolabial area reflects changes happening above it. Other patients may benefit from a conservative filler placed closer to the fold. The right location depends on the full facial assessment.
Hyaluronic acid filler may be dissolved with hyaluronidase when clinically appropriate. However, not every filler is reversible, and dissolving does not remove every procedural risk. Filler can cause bruising, swelling, infection, or a rare vascular complication, so provider training and complication readiness still matter.
A mirror check cannot replace an assessment, but it can help you describe what you see. Look at your face while it is relaxed, then smile, speak, and gently purse your lips.
Most faces show more than one pattern. That is why a plan may involve filler, Botox, both in stages, or no treatment.
At InjectCo, a nurse injector evaluates your face at rest and during expression. The assessment covers your medical history, prior treatments, facial symmetry, and goals.
You should leave knowing what creates the line and what each option can change. If lower-face Botox is considered, the injector will explain its off-label status, expected duration, and functional risks.
Meet with an InjectCo nurse injector for a facial assessment before choosing Botox, filler, or a staged combination.
Most questions about this part of the face come down to one distinction: whether the crease is driven by muscle movement or by lost volume and support, because that decides whether a wrinkle relaxer, a filler, or both make sense. The answers below cover how Botox and filler differ across smile lines, nasolabial folds, and marionette lines, what can happen when the small muscles of the lower face are treated, how long results around the mouth hold, and what to expect if you choose to treat nothing at all.
Botox may help when repeated muscle movement causes fine lines around the lips or pulls the corners of the mouth downward. It does not replace lost volume or restore the structural support involved in deeper nasolabial folds. The right treatment depends on what is creating the line rather than where it appears.
Botox does not typically correct nasolabial folds because these creases are usually related to facial structure, volume loss, and changes in cheek support. Dermal filler may be more appropriate when lost volume is the primary cause. Treating the surrounding muscles with Botox may alter facial movement, but it will not rebuild the support beneath the fold.
For onabotulinumtoxinA, treatment of the depressor anguli oris, or DAO, often uses approximately two to four units per side. However, Botox does not directly fill marionette lines. The final amount depends on muscle strength, facial symmetry, prior treatment response, and whether volume loss or skin laxity also contributes to the concern.
Dermal filler is generally more suitable for nasolabial folds caused by lost volume or reduced cheek support. Botox may be considered when fine lip lines or downward muscle pull contribute to the appearance. Some patients benefit from a combined plan because each treatment addresses a different cause.
Yes, temporary smile changes can occur if Botox affects a nearby muscle involved in speaking, drinking, or facial expression. The lower face contains several small muscles positioned close together, so precise dosing and placement are important. Any unevenness usually improves as the treatment wears off, but contact your injector if you notice an unexpected change.
Botox results around the mouth generally last about three to four months, although this highly active area may wear off sooner for some patients. Duration depends on the dose, muscles treated, metabolism, and individual response. Your injector can use your first treatment response to guide the timing of future appointments.
Yes. Botox may reduce excessive muscle pull, while filler can replace volume or support a deeper fold. A provider may perform the treatments together or stage them so the response to each can be evaluated before more product is added.
Nothing medically harmful happens if smile lines, nasolabial folds, or marionette lines are left untreated. These are normal facial features that may become more noticeable as collagen, facial volume, and skin elasticity change over time. Cosmetic treatment is optional and should only be considered if the lines bother you personally.
The best plan begins with an anatomical answer. An assessment may show that Botox fits one concern, filler fits another, or treatment is unnecessary. That clarity helps protect facial movement and your budget. Individual results vary.
Medical disclaimer: this article is general information and is not medical advice. Individual results vary. Dosing ranges are published references, not personal instructions. Discuss any treatment, its risks, expected duration, and alternatives with a qualified provider.
Talk with an InjectCo nurse injector about what creates your smile lines and which option, if any, fits your goals.
Dr. Allen earned his Doctor of Osteopathic Medicine at Lake Erie College of Osteopathic Medicine and completed his emergency medicine residency with Texas A&M. As Medical Director, he reviews InjectCo’s treatments, protocols, and patient education content for accuracy and safety across all nine Texas locations.
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