Gummy smile: how a small dose of Botox changes it

What is a gummy smile?

A gummy smile is simply one where more than 3mm of gum tissue shows when you smile. For some people this is only 1-2mm of exposure; for others it can be 5mm or more. It is not a defect or a problem unless it bothers you aesthetically. Many people have gummy smiles from birth; others develop them as their face changes with age.

The usual causes are either hyperactive muscles (the levator labii superioris muscles that pull the upper lip up too far), a short upper lip, excess gum tissue, or a combination of these. Botox works specifically on the muscular version. If your gummy smile is caused by the shape of your lip or jaw rather than muscle hyperactivity, Botox will not help.

How Botox relaxes the upper lip

Botox is a purified form of botulinum toxin that blocks signals between nerves and muscles. When injected into the levator labii superioris muscle (the main muscle responsible for lifting the upper lip), it prevents that muscle from contracting fully. The result is a gentler, less pronounced lift, which means less gum shows.

The injection points are small and specific. A qualified practitioner places tiny doses just above the bone, lateral to the nasal pyriform opening on each side of the face. The toxin then diffuses slightly into the target muscle over the following days, gradually relaxing it. You do not see the effect immediately; the smile becomes progressively softer over the first 2-4 weeks, with optimal results by week 3-4.

The dose precision problem

This is where most over-treatment happens. The levator labii is a small, delicate muscle. The difference between a natural-looking result and an over-treated stiffness is sometimes just 1-2 units of Botox.

The evidence supports starting with 1-2 units per side, with 2-3 units per side as a standard dose. Some practitioners use up to 5-6 units total, but this increases the risk of flattening the smile or creating asymmetry. At Visage, I favour conservative dosing and a two-week review over guessing at a higher initial dose.

The clinical data shows that a mean reduction of 2-2.5mm in visible gum is typical. For many people, this is enough to make a meaningful difference without any obvious change in how they smile. But if you inject too much, the upper lip does not lift at all, the smile loses its warmth, and the result looks frozen.

• · Too little: gum show barely changes.
• · Just right: gum show reduces by 2-3mm, smile still feels natural.
• · Too much: upper lip stays flat, smile looks stiff or lopsided.

Why this is not a good first-time treatment

Botox for gummy smile requires technical precision and good clinical judgment. If you have never had Botox before, I would normally recommend starting with a more forgiving area, such as the frown lines or crows feet. Those areas are larger, more muscular, and more tolerant of slight variation in dose.

The levator labii is different. It is small, the effect is immediately visible in your smile (you cannot hide it), and the dose range is narrow. If your practitioner gets it slightly wrong, you will notice every day for three to four months. For someone new to Botox, the anxiety of that possibility often outweighs the benefit.

Additionally, many first-time clients worry about whether Botox will work at all for them, or whether they will look "done". Gummy smile treatment adds a third worry: the question of whether your smile will feel and look normal. It is a lot to navigate in a single treatment.

What results actually look like

When Botox for gummy smile works well, the change is subtle. Your smile still moves freely. You can still show teeth, laugh, and express emotion normally. The only difference is that when you smile fully, less gum tissue is visible. If you showed 4-5mm of gum before, you might now show 1-2mm.

Most people report that family or friends do not notice the change, though they themselves feel much more confident. The results develop gradually over 2-4 weeks, stabilising by week 3-4. Effects typically last 3-4 months, after which the muscle gradually regains its strength and gum show returns to baseline.

If you are considering this treatment, book a consultation where the practitioner can assess your smile in detail. Not all gummy smiles respond equally well; some are caused by dental or jaw anatomy rather than muscle overactivity. A proper clinical assessment will tell you whether Botox is likely to help.

Regulatory and safety notes

In the UK, Botox is a prescription-only medicine. This means it must be prescribed by a qualified, regulated healthcare professional (such as a doctor, nurse prescriber, or dentist) before it is injected. The person who prescribes it must assess you in person. Remote prescribing is not permitted, and any clinic that offers it is not following the law.

Since August 2025, new licensing requirements mean that clinics offering Botox and other aesthetic procedures must now be locally licensed and supervised by a named regulated healthcare professional. This is a significant step forward for patient safety. When you choose a clinic, verify that they meet these requirements and can show you their regulatory credentials.

At Visage, all Botox is prescribed by me, a registered nurse with an MSc in Advanced Practice, and administered by qualified practitioners in my clinic. We use a low-dose, conservative approach to gummy smile treatment precisely because we believe precision matters more than speed.

In summary

Botox for gummy smile is effective when dosed carefully. The standard dose is 1-2 units per side, sometimes up to 3 units, and results typically reduce visible gum by 2-2.5mm. The key is precision: too much Botox flattens the smile and looks unnatural, while too little has no effect.

This is not an ideal first treatment for someone new to Botox because the margin for error is small and the result is visible in every smile. If you are interested in trying this treatment, choose a qualified practitioner with experience in this specific area, have realistic expectations about the timeline (results develop over weeks, not days), and be prepared for a two-week review appointment to assess whether a second dose is needed.

Common questions