Botox for a gummy smile: how many units, and why the dose is so low

People who look up how many units of toxin go into a gummy smile are usually trying to do some math: dose times price, or their dose compared with a friend's. The math doesn't work, and the reason is interesting.

The gummy smile takes one of the lowest doses on the entire face. While the forehead and glabella call for amounts that add up to dozens of units, here the work is done with a few units per side. A case report published in RFO UPF, a Brazilian dental journal, for example, describes 10 units on each side, injected beside the nostril, in the nasolabial fold.

And even that number is not a recipe. It is the record of one case, not a rule that transfers to your face. The right amount depends on things that only show up when someone watches you smile in person.

Why the dose here is so small

The muscles that lift the upper lip are thin, superficial and sit millimeters from muscles you use for everything — talking, smiling, eating. One extra unit spreading to the wrong place doesn't produce "a bit more result". It produces a lip that doesn't lift properly on one side, a crooked smile, a temporary difficulty pronouncing certain letters.

It is the opposite of the logic of the forehead, where the margin for error is generous and the consequence of getting the dose wrong is cosmetic. Here the consequence is functional.

That is why the practical rule for any treatment in the lower third of the face counts double with a gummy smile: inject less, then reassess. You can add later. You can't take it out.

What changes the number of units

There is no standard dose because there is no standard gummy smile. What the practitioner is reading before deciding:

• How much gum shows. Mild exposure and pronounced exposure don't call for the same thing — and pronounced exposure doesn't always call for more toxin; sometimes it calls for a different treatment.
• What causes it. Not every gummy smile comes from an overactive muscle. It can come from lip length, from altered passive eruption of the teeth, from the bony proportions of the upper jaw. Toxin only addresses the muscular component. This is decisive, and it is the subject of the article on the types of gummy smile.
• How strong your muscle is. Two people with the same gum exposure can have muscles of very different strength.
• Symmetry. It is common for one side to lift more than the other. In that case the dose is not the same on both sides — making it equal would create asymmetry.
• Whether you've been treated before. Regular sessions tend to produce a cumulative effect, and the maintenance dose is usually lower than the initial one.

At RUV, this is part of what Dr. Najla calls analyzing the whole face before treating the complaint. The complaint is "too much gum shows when I smile". The plan only takes shape after understanding what makes that gum show — and in a share of cases the honest answer is that toxin won't do much.

How Botox for a gummy smile is done

Without turning this into a lesson, because it isn't for you to do yourself: the toxin is placed at shallow points near the base of the nose, in the area where the muscles that lift the upper lip converge. The case report cited describes exactly that — the area marked beforehand, topical anesthetic first, injection beside the nostril.

What separates a good treatment from a bad one here is not the amount of product. It is the depth and the spacing between points. Too superficial, and the product spreads. Too deep or too far to the side, and it reaches muscle you need to smile.

Before that, at RUV, there is one more step: a Doppler ultrasound assessment. It exists to map the vascular structure of that specific area and, when there is previous filler in the nasolabial fold or around the nose, to identify where that material sits. Old filler changes how the tissue behaves and changes the plan. It isn't a brochure selling point — it is what turns "it's safe" into something verified, point by point, rather than assumed.

Where exactly it is injected

The short answer: at the points the assessment marks, near the side of the nose.

The useful answer: be wary of anyone who answers this on Instagram with a little map. The points change from face to face because the distribution of the muscles changes. Marking points without watching the person smile is guessing about an anatomy you don't know.

What 50 IU, 100 IU or 35 IU on the vial means

This question comes up a lot, and it's simpler than it looks. IU stands for international unit — the standardized measure of botulinum toxin potency. It is not volume, not milligrams, not "concentration". It is biological potency.

Vials on the market come in different presentations of total units. A 100 IU vial contains one hundred units in total; a 50 IU vial, fifty. The vial arrives as a powder and is diluted in saline at the time of use, and the dilution determines how many units are in each drop that leaves the syringe.

Two practical consequences:

• Units are not comparable between brands. Potency is defined by each manufacturer's own assay. Twenty units of one product are not necessarily equivalent to twenty of another. The brands registered in Brazil are listed in Anvisa's public product search, and it's worth checking which one is being used on you.
• The vial isn't yours. It is diluted and used within a short window. Thinking "there's product left over, it can be saved" doesn't match how the material behaves or safe practice.

How many treatments come out of one vial

It depends entirely on the presentation and on the areas treated in the same session. Because a gummy smile uses so little, it is almost never the only destination for a vial — it usually goes alongside other areas in the same appointment.

What that means for you in practice: you can't estimate cost by dividing the vial by the units. Anyone who tries to calculate it that way ends up with numbers that bear no relation to what actually happens in the appointment.

What goes into the cost, without talking numbers

Since the price question shows up in every search, it's worth answering what can be answered.

What makes up the price of a treatment: the brand and presentation of the product, the amount actually used, the assessment time — which, for a gummy smile, is the longest part of the appointment — the training of the person injecting, the follow-up reassessment included, and the clinic's setup, including the scans it runs before injecting.

What doesn't: the impression that a bigger dose means you're getting more. With a gummy smile, a bigger dose is usually a sign that someone didn't read the case well.

Does toxin fix a gummy smile?

It fixes part of it, and only when the cause is muscular. Within that scope, it works well and it works fast: published reports describe a visible reduction in gum exposure by the first reassessment, with peak effect between day seven and day fourteen.

When the cause is dental, skeletal or a matter of lip proportion, toxin delivers little or nothing. And this is where the criterion RUV treats as part of the job, not a courtesy, comes in: saying so up front, at the assessment, not after two sessions that changed nothing.

How long it lasts

The literature describes effects lasting up to six months, with an average of three to four months. The case published in the Spanish journal reports the result holding for six months without another treatment.

Worth noting: because the gummy smile dose is low, it's reasonable for the duration to sit toward the shorter end of that range. That is the price of doing it right — and it's a price worth paying, because the alternative is a smile that doesn't work for three months.

And the other doses that show up in search

Three neighboring questions that come up alongside this one, answered directly so you don't mix up the numbers:

• Lip flip. A different procedure — it relaxes the muscle around the mouth so the upper lip turns out slightly. Also a low dose, and for the same reason: thin muscle with a role in speech.
• Bruxism and masseter. Here the picture reverses. The masseter is one of the strongest muscles in the body and calls for substantially higher doses than any point on the upper face. Comparing masseter units with gummy smile units makes no sense at all.
• Jawline contour. Toxin along the jawline acts on a specific neck muscle that pulls the corner of the mouth down. A subtle effect, it helps some faces, and it doesn't replace contour projection.

Each area has its own dose because each muscle has its own strength and function. There is no single number for "how many units of Botox".

What natural means here

The quality of a gummy smile treatment isn't measured by how much gum disappeared. It's measured by what stayed intact: the symmetry of the smile, the mobility of the lip, your speech.

A gummy smile treated well is still your smile, with less gum showing. Treated with a high dose, it becomes a heavy lip that lifts little and lifts crooked — and that, unlike the photo on a screen, everyone notices in person.

When we advise against it

• When the cause isn't muscular. Altered passive eruption, vertical maxillary excess or an anatomically short lip don't respond to toxin. Insisting wastes time and delays the real solution.
• When the expectation is to eliminate gum exposure completely. Toxin reduces how far the lip lifts. It doesn't change bone or tooth height.
• A touch-up before the reassessment. The result is still forming; the assessment window described in the reports is two weeks or more.
• When a previous treatment in this area already caused significant asymmetry. In that case the first step is understanding what happened, not repeating it.
• Pregnancy and breastfeeding. An elective procedure waits.

Frequently asked questions

How many units of Botox for a gummy smile?

A few per side. One published case report describes 10 units on each side. But the dose is set at the assessment, watching your smile in motion — and when in doubt, the right call is to start lower and reassess.

What does IU mean for Botox?

International unit, the standardized measure of toxin potency. It doesn't correspond to volume or weight, and it isn't comparable between brands.

How many treatments come out of one vial?

It depends on the presentation and on which areas are treated in the same session. A gummy smile uses little and is rarely the only destination for a vial.

Can Botox fix a gummy smile for good?

No. The effect is temporary — the literature describes an average of three to four months, and up to six. A permanent solution, when the cause isn't muscular, involves other approaches.

Does it hurt?

It's done with a fine needle and topical anesthetic beforehand. Brief discomfort, easily tolerable.

How long until I see a difference?

The effect starts in the first few days and peaks between day seven and day fourteen. The result is assessed in that window, not before.

Why is my smile crooked after the treatment?

Usually because the dose was too high or a point was too far to the side, reaching a neighboring muscle. There is no reversal agent for toxin — what there is is time, and in some cases technical compensation in the muscles on the other side while the effect wears off. That is exactly why less is injected.