Dimpled chin after Botox: why it happens and how long it lasts

The chin is sometimes treated with botulinum toxin to relax the mentalis muscle, whose contractions crease the skin and give it a dimpled, "orange peel", "cobblestone" or "golf ball" appearance^1,3. This indication appears in expert consensus documents^1,5, but no French label provides for it: it is an off-label use^6,8. Sometimes the result is not the one expected: the dimples remain visible, or a new bump appears when you press your lips together. This is one of the chin problems after an injection. Here are the answers to the seven questions people ask most often.

Why does the chin stay dimpled or become bumpy?

The orange-peel look of the chin comes from contractions of the mentalis, a small muscle under the skin of the chin that pushes it up when you pout or press your lips together³. Treatment aims to relax this muscle. Two situations can explain a disappointing result.

The first is paradoxical bulging. When the muscle is only partly or unevenly relaxed, the fibres that remain active keep contracting on their own and make part of the chin stand out. An expert consensus on the lower face lists this bulging among the possible complications¹. A case was published in 2020: in a 26-year-old woman treated for a cobblestone chin, an unusual bulge appeared on the chin the day after the injection³. The authors attribute it to an imbalanced relaxation of the muscle, linked to the injection technique and to uneven spread of the toxin³.

The second is an effect felt to be insufficient: once the effect has set in, the dimples are still visible. Our sources do not describe this situation for the chin. It is a question to ask the doctor who performed the injection.

The chin is a delicate area, because its muscles are also used to speak, eat and close the mouth¹. An anatomical review stresses the importance of precise landmarks to inject the mentalis without affecting the neighbouring lip muscles².

Peeling skin on the chin is not among the effects of the toxin described in the sources we consulted. If that is what you notice, show it to the doctor.

How soon after the injection does it appear?

Paradoxical bulging can appear very early: in the published case, the day after the injection³. More generally, the labels state that side effects usually occur in the first few days after the injection⁶. To judge dimpling that persists, you need to wait until the effect has set in: for the approved areas, the type A labels describe an improvement within a few days⁶. No source gives a timeframe specific to the chin.

How long does it last?

At most, as long as the effect of the toxin. The labels give no duration for the chin, which is not one of the approved indications; for the approved areas, the effect of a type A toxin has been shown for up to 4 months after the injection⁶. In the published case, the bump was clearly reduced by an additional injection, without waiting for the effect to wear off³. To understand what this duration depends on, see the page on how long the effect of botulinum toxin lasts.

Is it reversible?

Yes. The effect of botulinum toxin is temporary: transmission between nerve and muscle gradually recovers, first through small nerve sprouts, then through the return of the original nerve terminal⁷. The chin muscle gradually regains its activity, and the chin its appearance before the injection, dimples included.

Is there a treatment?

No product reverses the effect of the toxin. For paradoxical bulging, the published case describes an additional injection of toxin into the mentalis fibres that remained active, located by ultrasound, with a clear improvement in the contour of the chin³. This is a single case, not a trial: such a correction is decided in consultation, after an examination.

Prevention depends on technique. The authors of the case recommend treating the whole thickness of the muscle to avoid an imbalanced relaxation³. A 2026 review considers that ultrasound guidance can reduce paradoxical bulging and asymmetry after injections into the lower face muscles⁴.

What should you avoid?

• Do not ask for a new injection elsewhere without saying so: muscle weakness may be made worse by another toxin injected before the effect of the previous one has worn off^6,8. Always mention the date of the last session and the product used.
• Do not mistake the bump for a lump of product to be massaged: the toxin does not add volume, it is the muscle contracting^1,3.
• Do not confuse this problem of appearance with difficulty closing the mouth, drinking or speaking clearly, which has a different mechanism and should be reported to the doctor².

When should you see a doctor?

Talk to the doctor who performed the injection if a bump appears or if the dimples bother you: they will examine the chin at rest and when you press your lips together, and tell you whether to wait or consider a correction. Photos of the chin at rest and when contracted, taken a few days apart, will help them judge how it is changing.

See a doctor sooner if your mouth does not close properly, your lower lip droops or your smile becomes uneven: an anatomical review lists these effects of a poorly placed injection in the chin².

A chin that no longer moves at all is covered on the page about the stiff chin after an injection, a crooked lip on the page about uneven lips after an injection.