DAO Botox is a small, carefully targeted lower-face treatment used to soften a muscular downward pull at the corners of the mouth. The aim is a more neutral resting expression, not a frozen smile or a dramatic lift. Because the muscles around the lips overlap and work together during speech, eating and expression, conservative assessment matters more than simply adding more toxin.
This guide explains what the DAO muscle does, who treatment may suit and what to expect afterwards. View the Dr Motox DAO treatment page or book a consultation.
What is the DAO muscle?
DAO stands for depressor anguli oris. It is a paired muscle running from the lower jaw towards each corner of the mouth. When it contracts, it helps pull the mouth corners downwards. That movement is normal and forms part of facial expression.
In some people, a naturally strong DAO creates a downturned appearance even when the face is relaxed. The effect may become more noticeable as facial tissues change with age. However, not every downturned corner is caused mainly by muscle: volume loss, skin laxity, dental support, chin position and surrounding muscle balance can all contribute.
How does DAO Botox work?
Botulinum toxin type A temporarily reduces the chemical signal between a nerve and a muscle. In simple terms, the treated muscle contracts less strongly. When a carefully selected dose is placed into the DAO, the downward pull may soften and the mouth corners can rest in a more neutral position.
The change should be subtle. DAO Botox does not physically lift the face, fill marionette lines or add lip volume. It also cannot guarantee symmetry because everyone starts with differences in muscle strength, bone structure and soft tissue. The aim is improvement, not mathematical sameness.
Cosmetic DAO treatment is an off-label use of botulinum toxin in the UK. This means it is outside the product’s specifically licensed cosmetic indications, not that it is automatically inappropriate. It requires an informed discussion, individual prescribing and treatment by an appropriately qualified practitioner.
Who may be suitable for DAO Botox?
Treatment may suit an adult whose mouth corners turn down mainly because of active DAO contraction. During consultation, the clinician should observe the face at rest and in movement, including smiling, speaking and pulling the corners down. That dynamic assessment helps separate muscular pull from volume loss or laxity.
A person seeking a gentle change, who understands the temporary result and accepts that perfect symmetry is impossible, is more likely to have realistic expectations. Combining treatments is not always necessary.
When another treatment may be better
If the main issue is a deep fold, loss of support or loose skin, relaxing the DAO alone may achieve little. Carefully planned dermal filler, skin-quality treatment or no treatment may be more appropriate. A lip flip is different again: it targets muscles around the upper lip to create a small outward roll, rather than treating the downward pull of the mouth corners.
Why precision is especially important
The DAO partially overlaps with the depressor labii inferioris, or DLI, which helps move the lower lip. Anatomical research shows why position and depth matter: unintended spread into nearby muscles can alter the smile, lower-lip movement, speech or the way a person drinks from a cup. Lower-face treatment is therefore normally cautious and anatomy-led.
Possible unwanted effects include asymmetry, an uneven smile, lower-lip weakness, difficulty with certain mouth movements, bruising, swelling, tenderness or headache. These effects are usually temporary, but contact the clinic promptly if eating, drinking, speaking or smiling feels significantly different.
What happens after DAO Botox?
The injections are usually quick. Small bumps, redness or bruising can occur. Early change may begin after several days, with the result developing over roughly 3–14 days. Dr Motox reviews and complimentary adjustments, when clinically appropriate, take place within the clinic’s three-week window.
Many people notice benefit for around two to four months, although lower-face doses are deliberately small and may wear away sooner. Movement returns progressively; stopping treatment does not make the muscle permanently worse.
Aftercare and hydration
Follow the instructions given by your clinician. Avoid rubbing or pressing the injection area and ask when to resume strenuous exercise, alcohol, heat exposure, facials and active skincare. Do not apply make-up or skincare over puncture sites until they have closed.
Once the skin is closed and calm, gentle hydration can return to the routine. The Dr Motox Exosome Collagen Face & Neck Sheet Mask is a staple hydration option suitable for dry, oily and sensitive skin. It does not change the toxin result, but it can support a comfortable skincare routine. Patch test first and avoid use on infected, broken or actively inflamed skin. Our post-treatment hydration guide gives a simple barrier-conscious routine.
Who should avoid or postpone treatment?
Botulinum toxin is not carried out during pregnancy. Treatment is also postponed when there is infection or active inflammation at the proposed injection site. Tell the clinician about breastfeeding, neuromuscular conditions, previous reactions to toxin, facial weakness, swallowing problems and all medicines, particularly those that can affect nerve-to-muscle signalling. If you are unwell, assessment may be deferred.
DAO Botox FAQs
Will it lift my mouth corners?
It may allow the corners to sit more neutrally when a strong DAO is the main cause. It is not a surgical lift and cannot correct every cause of downturn.
Can DAO Botox change my smile?
It can if toxin reaches nearby lower-lip muscles. Careful assessment and conservative placement reduce that risk but cannot remove it entirely.
How much is DAO Botox at Dr Motox?
Standalone DAO Botox is currently £100. Prices can change, so confirm the amount shown when booking.
Is it the same as masseter Botox?
No. DAO treatment targets mouth-corner movement, whereas masseter treatment addresses the large chewing muscles. Read our masseter Botox guide for that separate treatment.
Evidence and safety references
The 2021 three-dimensional DAO and DLI anatomy study explains their overlap, while a 2024 ultrasound investigation examined DAO position to improve targeting precision. The official UK BOTOX Summary of Product Characteristics confirms that it is prescription-only, units are not interchangeable between products and administration requires an appropriately qualified healthcare practitioner.
This article is educational and does not replace a medical consultation. Botulinum toxin is a prescription-only medicine; benefits, limitations and risks must be assessed individually.
