Marionette Lines Botox®: A Solution for Youthful-Looking Skin

By Jeff Russell, Executive Director, IAPAM • Last updated: September 2026

Marionette lines, those vertical creases that run downward from the corners of the mouth, can give a tired or unhappy look to an otherwise rested face. Botox® offers a non-surgical way to address the muscular half of that problem and soften the effect.

By targeting the underlying muscle contractions that contribute to the formation of marionette lines, Botox® can help relieve the downward pull on the mouth and create a smoother, more neutral resting expression. The muscle doing that pulling has a name — the depressor anguli oris, usually shortened to DAO — and almost everything that matters clinically about this treatment comes back to it.

This guide covers what patients want to know and what injectors need to know: where the DAO actually sits, how it is dosed, why the effect fades faster here than on the forehead, why this use is off-label, and where the single most common complication comes from.

Key Takeaways

Where to Inject Botox® for Marionette Lines

When it comes to injecting Botox® for marionette lines, precision matters more than dose. Skilled injectors place small amounts of Botox® into the muscle responsible for pulling down the corners of the mouth. By selectively relaxing it, Botox® relieves the downward pull, producing a subtle lift and a softening of the marionette line. The exact injection site varies with an individual’s facial anatomy, and a skilled injector will assess the area carefully before treating.

The muscle you are actually treating: the depressor anguli oris

The DAO is a triangular muscle that originates along the jawline at the mental tubercle and converges upward toward the modiolus, the dense knot of muscle at the corner of the mouth where several perioral muscles meet. Published anatomical work puts its width at the base at roughly 3.6 cm, with its inner border sitting about 1.5 cm to the side of the chin’s midline.

Two things about that anatomy drive everything else. First, the DAO is superficial — measured at 0.25 to 0.4 cm from the skin surface — so this is an intradermal or subdermal injection, not a deep one. Second, its inner edge overlaps the depressor labii inferioris (DLI), the muscle that pulls the lower lip down. Those two muscles sitting shoulder to shoulder is the reason nearly every complication in this area happens. A solid grounding in facial anatomy for Botox® injection sites is not optional for lower-face work.

Finding the injection point

The published anatomic proposal locates the injection point at the intersection of two lines: a vertical line dropped from the mid-pupil, and a horizontal line at the midpoint between the lower border of the mandible and a line drawn from the corner of the mouth to the tragus of the ear. That intersection sits reliably within the belly of the DAO and well away from its inner border.

The line you should not cross

How Many Units of Botox® for Marionette Lines?

This is a small-dose area. A prospective study published in 2026 followed 51 patients with drooping mouth corners and compared the older single-point technique against a three-point pattern, then worked out an optimal dose for each severity band.

The practical read: start low. A conservative 2–3 units per side treats the majority of mild cases and leaves room to add at the two-week review. Chasing a severe case with escalating units is, on this evidence, the wrong lever to pull.

Single-Point vs. Three-Point Technique

The same 2026 study is the reason technique now deserves its own conversation. Every patient received a single-point 3-unit injection per side first, then later a triangular three-point pattern with the dose distributed across the three points and scaled to severity. At four weeks, the three-point technique produced significantly greater improvement in both the vertical distance from the mouth corner to the pupillary line and the angle of drooping. No adverse events were reported in the series.

Spreading the dose across the muscle belly rather than concentrating it at one point appears to relax the DAO more evenly — which is what you would expect from a flat, fan-shaped muscle. For injectors, it is a straightforward technique upgrade that costs nothing extra in product.

How Long Does Botox® for Marionette Lines Last?

Shorter than the forehead, and it is worth setting that expectation honestly. Patients commonly describe three to four months, but the 2026 prospective study measured the treated mouth corners back at baseline by 12 weeks. Small, constantly active perioral muscles tend to recover sooner than the large upper-face muscles, so planning maintenance treatments around the 12-week mark is more realistic than promising four months and under-delivering.

Is Botox® for Marionette Lines FDA-Approved?

No — and any practitioner-facing discussion of this treatment should say so plainly. BOTOX® Cosmetic carries four aesthetic indications, and the lower face is not among them.

Off-label use of an approved drug is lawful and routine in aesthetic medicine. What changes is where the responsibility sits: with no labelled dose to fall back on, the provider owns the clinical judgement, the consent conversation and the documentation. Injectors working through a full-face treatment strategy should be able to say, out loud and to the patient, which parts of the plan are on-label and which are not.

What Is Better for Marionette Lines: Botox® or Fillers?

The honest answer is that they treat different halves of the same problem, which is why the question is usually a false choice.

Botox® addresses the dynamic component — the active downward pull of the DAO. Relaxing that muscle lets the corner of the mouth sit in a more neutral position and takes the tension off the crease. It works best in patients whose marionette lines are driven primarily by muscle movement, and in younger patients who still have good volume.

The marionette line itself, though, is largely a static structure — anatomically it is often called the labiomandibular or melomental fold, and it deepens as the tissue above and beside it loses volume and support. Dermal fillers restore that volume, lifting and softening the groove directly. Products such as Restylane® and other hyaluronic acid fillers are the usual tools here.

Published work comparing the two found that combination therapy produced significantly greater cosmetic improvement than filler alone at both two and four weeks. In practice that combination — toxin to release the pull, filler to rebuild the support — is what most patients with established marionette lines need. Relaxing the DAO on a face that has lost significant volume will soften the expression but will not fill the groove, and a patient told otherwise will be disappointed.

Consultation and Choosing a Qualified Injector

Before undergoing any treatment for marionette lines, consult a qualified and experienced medical professional. They should evaluate your specific concerns, explain the options, and recommend an approach based on your anatomy and your goals — including whether the driver is muscle, volume, or both. Choosing an injector with genuine expertise in lower-face anatomy is what separates a natural result from an uneven smile, and it is a fair question to ask directly: how often do you treat this area, and what is your protocol?

For clinicians, the lower face is where general injection confidence stops being enough. The margins are measured in millimetres, the neighbouring muscle changes a patient’s smile if you reach it, and there is no label to tell you the dose. That is exactly the kind of work that benefits from supervised, hands-on practice rather than video learning alone — the same reason perioral technique and treatment around the smile lines are taught with live models.

Frequently Asked Questions

Which muscle does Botox® target for marionette lines?

The depressor anguli oris, or DAO. It is a thin triangular muscle that runs from the jawline up to the corner of the mouth, and its job is to pull that corner downward. Relaxing it removes the downward pull so the corner of the mouth sits in a more neutral position. The DAO sits very superficially, roughly 2.5 to 4 millimetres below the skin surface.

How many units of Botox® are used for marionette lines?

Published protocols range from a conservative 2 to 3 units per side at a single point, up to severity-based dosing of 3 units per side for mild drooping, 6 units for moderate and 12 units for severe. A 2026 prospective study found that even 15 units per side did not satisfactorily correct the most severe cases, which suggests those patients need a combination approach rather than more toxin. Dosing is always individualised and units are not interchangeable between products.

Is Botox® FDA-approved for marionette lines?

No. BOTOX® Cosmetic is FDA-approved for four areas only: moderate to severe glabellar lines at 20 units, lateral canthal lines at 24 units, forehead lines at 20 units, and platysma bands, which were added in October 2024. Treating the depressor anguli oris for marionette lines is an off-label use. Off-label does not mean improper, but it does mean the provider carries the clinical judgement and the consent conversation.

How long does Botox® for marionette lines last?

Expect a shorter run than the forehead. A 2026 prospective study of 51 patients measured the mouth corner back at baseline by 12 weeks. Patients often describe three to four months, but the lower face tends to fade sooner because these are small, constantly active muscles. Planning maintenance at roughly the 12-week mark is more realistic than promising four months.

What is the most common side effect of DAO Botox®?

An asymmetric or uneven smile. It happens when the toxin spreads to the depressor labii inferioris, the muscle that sits just medial to the DAO and pulls the lower lip down. The published safeguard is to keep every injection lateral to the vertical line dropped from the corner of the mouth, and to stay superficial. Reported cases resolve as the toxin wears off, and patients in the published series did not report difficulty chewing or speaking.

Is Botox® or filler better for marionette lines?

They treat different halves of the same problem, which is why most patients need both. Botox® addresses the dynamic component, the active downward pull of the DAO. The marionette groove itself is largely a static loss of volume and support, and that needs a filler. Published work comparing combination treatment against filler alone found significantly greater improvement with the combination at two and four weeks.

Botox® for Marionette Lines: Conclusion

Botox® is an effective, non-surgical option for the muscular component of marionette lines — provided the injector knows the muscle, respects the millimetres, and is candid with the patient about what toxin can and cannot do on its own. Used alone in the right patient, or in combination with a filler in most, it softens the downward pull and restores a more rested resting expression.

Lower-face work is where anatomy knowledge earns its keep. IAPAM’s hands-on Botox® training is taught by board-certified dermatologists with live-model practice in a clean clinic setting in Scottsdale, Arizona — the setting where perioral technique is actually learned. If you want to sample the teaching first, the free module below carries 1 AMA PRA Category 1 CME at no cost.

Get Your Free Botox® Module + 1 CME

Disclaimer: This guide is for informational and educational purposes only and does not constitute medical advice. Treating the depressor anguli oris with botulinum toxin is an off-label use. Treatment plans, injection techniques, and dosing must be tailored to each patient by a qualified, licensed provider. Always follow product labeling, your scope of practice, and your state medical and nursing board regulations.