Lip flip: Botox for the lips and lines around the mouth

The lips are one of the eleven areas of our atlas of botulinum toxin, area by area. This page presents the two most common uses around the mouth, what the toxin can and cannot do, what studies say, and why these uses are off-label in France. It does not replace a consultation.

Why are the lips treated?

Around the mouth, a ring of muscle, the orbicularis oris, closes the lips, purses them and pushes them forward. It is this muscle that is targeted, in two different ways.

First use: the vertical lines on the upper lip, sometimes called "barcode lines", which show when you purse your lips. They are related to the activity of the orbicularis oris¹. Relaxing this muscle slightly makes them less visible in motion. A trial published in 2012 studied this use in 60 women¹.

Second use: the lip flip. A small amount of toxin is injected along the border of the upper lip, so that it turns slightly outwards². The stated aim is to improve the contour of the lip, its eversion and the impression of a fuller lip², without injecting a filler.

The mouth area is also covered by a 2004 expert consensus on botulinum toxin in aesthetics³.

What the toxin does not do: it does not increase lip volume and does not replace a filler. Nor does it treat lines that are very deep at rest in the same way as lines that form with movement.

When is the toxin used?

No French label provides for this area, so there are no official criteria. For upper lip lines, the 2012 trial concerned "dynamic" lines, that is, lines visible in motion¹. For the lip flip, a 2021 publication asks whether interest in it is truly rising and notes that the literature remains very limited².

The contraindications in the labels apply whatever the area: allergy to the toxin or to a component of the product, a generalised disorder of the muscles and of the junction between nerve and muscle (myasthenia gravis, Lambert-Eaton syndrome), an infection at the injection site^4,5. Treatment is not recommended during pregnancy or breastfeeding^4,5.

Which toxin for the lips?

The type A toxins approved for aesthetic use in France cover frown lines and, depending on the product, crow’s feet and forehead lines^5,6. None provides for the lips. The short-acting botulinum toxin (serotype E) is approved for frown lines only, in the European Union and in Canada^4,7. For this area, any injection is therefore off-label. The studies cited concern type A toxins^1,2.

Is it right for me?

Your doctor will look at your lips at rest and in motion, how your upper lip turns outwards when you smile, how much gum shows, and your habits: speaking a lot in public or playing a wind instrument, for example, are worth mentioning. They will take into account your medical history, your treatments and any pregnancy plans.

If your concern is mainly the gum showing when you smile, the page on the gummy smile deals with that question. If it is your chin that tenses, see the page on the chin.

Questions to ask your doctor: is this treatment off-label? What result is reasonable? Will I be able to drink, speak and whistle normally? What happens if one side of the lip is more relaxed than the other?

Onset and duration

No label gives an onset or duration for this area. For upper lip lines, the 2012 trial observed a reduction in their severity up to week 16 with the lower of the two doses tested, and up to week 20 with the higher dose¹. For the lip flip, we found no figures in any reliable source.

How these timelines work in general is explained on the page about how long botulinum toxin takes to work.

What are the risks in this area?

The mouth is used to speak, eat, drink and kiss. Relaxing the orbicularis oris can therefore have functional consequences. In the 2012 trial, most side effects were mild to moderate, typical of lip treatment, and more frequent with the higher dose¹; the abstract does not detail them. A type A label points out, for a neighbouring area, that an injection too close to the zygomaticus major can make the lip droop⁶. Injection-site reactions (pain, swelling, small bruise) are also possible⁴.

Difficulty swallowing, speaking or breathing requires immediate medical attention⁴. If you are not happy with the result, for example an uneven lip, the page on the lips after an injection describes the most common situations.