Stiff chin after Botox: why, how long and what to do

The chin is treated with botulinum toxin to relax the mentalis muscle, which causes the "orange peel" or "golf ball" look of the chin when you press your lips together¹. Sometimes the result goes further than intended: the chin looks frozen, the lower lip moves less, drinking through a straw becomes difficult. This is one of the chin problems after a botulinum toxin injection described by experts. It is bothersome, sometimes visible when you speak or smile, but it is temporary. Here are the answers to the seven questions people ask most often.

Why does the chin look frozen?

The mentalis muscle raises the chin and pushes the lower lip upwards. Right next to it is the depressor labii inferioris, which pulls the lip down when you speak or smile. Chin treatment aims to relax the first without affecting the second.

An expert consensus on the lower face describes the situations that give the impression of a frozen chin¹:

• toxin spreading to the muscle around the mouth, which hampers lip movement: people may then find it hard to eat, drink through a straw or brush their teeth;
• an injection placed too far to the side, or spread to the depressor of the lower lip, which can make the lip uneven;
• a muscle relaxed only partly or unevenly, which can form a paradoxical bulge.

For this reason, these experts recommend keeping the injection points away from the mouth, to preserve speech and sucking¹.

It is also worth knowing that the chin is not among the areas covered by the French product labels: type A toxins are approved there in aesthetic use for frown lines and, depending on the product, for crow’s feet and the forehead². Chin treatment is therefore an off-label use.

How soon after the injection does it appear?

It appears as the effect of the toxin builds up. The labels state that side effects are usually seen in the first few days after the injection², and the US label of a type A toxin that they occur within the first week⁴. No source gives a timeframe specific to the chin.

How long does it last?

It lasts at most as long as the effect of the toxin injected. The labels give no duration for the chin, since it is not an approved indication; for approved areas, the effect of a type A toxin has been shown for up to 4 months after the injection². In a review of 35 studies, the lip asymmetries and imbalances linked to lower-face treatment all resolved on their own³. To understand what this duration depends on, see the page about how long botulinum toxin lasts.

Is it reversible?

Yes. The effect of botulinum toxin is temporary: transmission between nerve and muscle is gradually restored, first through small nerve sprouts, then by the return of the original nerve ending⁵. The chin and the lip regain their movement as the effect wears off.

Is there a treatment?

No product reverses the effect of the toxin; in most cases you have to wait. When a lip has become uneven, the expert consensus describes a correction with a small injection into the depressor of the lower lip on the opposite side, to restore balance¹. This practice has not been assessed in a trial; it is decided only during a consultation, after an examination. No massage or exercise has shown any effect in the sources we consulted.

What should you avoid?

• Do not ask for another injection soon afterwards to "unlock" the chin: the effect of toxins given a few months apart is not known, and muscle weakness can be made worse by another toxin injected before the effect of the previous one has worn off^4,6.
• Do not force yourself to drink through a straw or whistle if this makes you choke; use a cup and take small sips instead.
• Do not confuse a less mobile lip with difficulty swallowing: the latter is a warning sign.

When should you see a doctor?

Talk to the doctor who performed the injection as soon as the problem appears, especially if you have trouble eating, drinking or speaking clearly: they will check that it really is an effect of the toxin and tell you whether you simply need to wait. Write down the date of the injection and the day the problem started.

A crooked lip is covered on the page about uneven lips after an injection. If the problem extends down to the neck, see the page on the stiff neck after an injection.