What Is a Lip Flip with Botulinum Toxin?
If you have been looking into lip treatments recently, you may have come across the term lip flip with botulinum toxin. It is a subtle treatment that uses a small amount of botulinum toxin around the upper lip to relax specific muscles. Rather than adding volume like lip filler, a lip flip allows the upper lip to roll slightly outward, making more of the natural pink part of the lip visible.
For some people, this small change can create exactly the more defined, natural-looking lip they are hoping for. For others, a lip flip may not provide the type of enhancement they have in mind. So, before deciding whether it is right for you, here are five important things I think you should understand.
Tip 1: Understand What a Lip Flip Can and Can’t Do
The first thing to understand is that a lip flip is not a lip filler treatment.
Botulinum toxin is injected into carefully selected muscles around the upper lip. These muscles are involved in pursing and tightening the lips. By temporarily relaxing some of that muscle activity, the upper lip can roll slightly outward.
This can make more of the upper lip visible.
The important point is that the lip itself has not been filled or enlarged. No additional volume is being placed into the lip.
That is why I often explain a lip flip as a change in lip show rather than lip volume.
Does a lip flip make your lips bigger?
This is probably one of the most common questions.
The short answer is: not in the same way as lip filler.
Your lips may look slightly fuller because more of the natural lip surface becomes visible. However, a lip flip does not add volume to the tissue.
This difference matters because someone who wants a much fuller lip may be disappointed with a lip flip if they are expecting a filler-like result.
Recent research supports this distinction. A small 2026 prospective study found a modest increase in upper-lip height after treatment, but no measurable increase in lip volume. The study involved only 17 women, so it is useful evidence, but it should not be taken as proof that every patient will have the same result.
For me, the most important part is matching the treatment to the problem you actually want to change.
Tip 2: Know Whether Your Lip Anatomy Is Suitable
A lip flip with botulinum toxin can be useful for some patients, but it is not suitable for everyone.
When I assess someone for this treatment, I don’t just look at the lips when they are relaxed. I also want to see what happens when they smile and move their mouth.
How much of the upper lip is naturally visible? Does the upper lip roll inward when smiling? How active are the muscles around the mouth? Has the patient had lip filler before?
These details can all affect the result.
Why does the upper lip disappear when you smile?
This is something I hear quite often.
Some people have a good amount of lip tissue when their face is relaxed, but when they smile, the upper lip turns inward and much of the pink part disappears.
The way your lip moves is influenced by your individual anatomy and muscle attachments. The size and activity of the muscles around the mouth also play a role.
For someone whose main concern is that their upper lip becomes less visible when smiling, a lip flip with botulinum toxin may be worth discussing.
However, that does not mean that everyone with this concern needs a lip flip.
Sometimes the issue is actually a lack of lip volume. In that situation, dermal filler may be more appropriate. In other cases, another treatment or no treatment at all may be the best option.
That is why I believe an assessment is more useful than simply choosing a treatment because it is currently popular.
Tip 3: Understand the Difference Between a Lip Flip and Lip Filler
The terms lip flip and lip filler are sometimes used as though they are the same thing.
They are not. They work in very different ways. Here is a comparative table:
| Lip Flip | Lip Filler | |
|---|---|---|
| Main purpose | Changes upper-lip position and show | Adds volume and can alter shape |
| Treatment | Botulinum toxin | Dermal filler |
| Adds volume? | No | Yes |
| Main effect | More of the natural lip may become visible | Fuller or reshaped lips |
| Best suited to | Subtle change in upper-lip show | Patients wanting additional volume or shape |
If your concern is that your upper lip seems to disappear when you smile, a lip flip may be worth considering.
If your concern is that your lips genuinely lack volume, filler may be a better match.
You can read more about the different approaches to lip augmentation and dermal fillers on our website.
Can you have a lip flip and lip filler together?
Sometimes, yes. The two treatments can address different aspects of the lips. Filler can provide volume or shape, while a lip flip can alter the way the upper lip moves and sits.
However, combining treatments is not automatically better.
I prefer to start with the question: what are we actually trying to achieve?
If one treatment can achieve the desired result, there is no reason to add another simply because it is available.
The aim should always be a balanced result that suits your face, rather than doing as much treatment as possible.
Tip 4: Know What the Treatment and Recovery Are Really Like
A lip flip with botulinum toxin is a relatively quick treatment.
The first step, however, should be a proper consultation. We discuss what you would like to change, examine your lips at rest and during movement, and talk about what is realistically achievable.
The treatment itself involves a small amount of botulinum toxin being placed at carefully selected points around the upper lip.
The area around the mouth is particularly important for everyday functions such as speaking, eating, drinking and forming expressions. That is why precision matters.
What is the recovery like?
There is generally little conventional downtime following treatment.
You may have some temporary redness, tenderness or swelling at the injection points. Bruising can also occur, although it is not common in every patient.
The important thing to remember is that you will not see the final effect immediately.
The effect of botulinum toxin develops gradually. At Castleknock Cosmetic Clinic, I advise patients on what to do during the first 24 hours to help the treatment settle as intended.
This includes avoiding unnecessary pressure, rubbing or massage of the treated area. I also advise patients to follow the specific aftercare instructions they receive following their treatment.
When will I see the results?
The effect begins to develop over several days.
In general, patients can start to notice a change after around 5–7 days, with the result becoming more apparent over the following couple of weeks.
It is therefore important not to judge the treatment too soon.
A lip flip is also deliberately subtle. The aim is not to create a dramatic overnight change, but to make a measured difference to the way the upper lip sits and shows.
Tip 5: Understand the Potential Side Effects and How Long the Result Lasts
Like any medical treatment, a lip flip has potential side effects.
Most immediate effects are minor and temporary. These can include redness, tenderness, swelling or, occasionally, bruising at the injection sites.
Because the treatment works by relaxing muscles around the mouth, you may also notice a temporary change in how your upper lip moves.
If the muscles are weakened more than intended, some patients can experience changes to functions involving the lips, such as drinking from a cup or using a straw.
This is one of the reasons I place so much importance on careful assessment, accurate treatment and appropriate dosing.
If you have any unexpected or concerning symptoms after treatment, you should contact the qualified aesthetic doctor who treated you.
How long does a lip flip last?
The effect of a botulinum toxin lip flip is temporary.
The muscles around the mouth are used constantly when we speak, smile and eat. As the effect of the toxin gradually wears off, normal muscle activity returns.
In my experience, patients generally see the effect for around 8–12 weeks, although this can vary from person to person.
Some people may notice that the effect lasts closer to three months, while others may see it wear off sooner.
There is no need to repeat treatment simply because a certain number of weeks has passed. If you like the result and want to maintain it, the timing of further treatment can be discussed during a review.
Is a Lip Flip Right for You?
A lip flip is not simply a treatment for “small lips”.
It is better thought of as a treatment that can help show more of the natural upper lip by changing the way the lip moves.
If your main concern is that your upper lip rolls inward or becomes less visible when you smile, a lip flip may be something worth discussing.
If your concern is a lack of actual lip volume, a different approach may be more suitable. This could include dermal filler or, in selected cases, another form of lip enhancement.
The most important thing is to understand what you want to change before deciding how to treat it.
At Castleknock Cosmetic Clinic, I assess the movement, proportions and natural anatomy of your lips before recommending whether a lip flip is appropriate.
Frequently Asked Questions About Lip Flips
What is a lip flip?
A lip flip uses a small amount of botulinum toxin to temporarily relax selected muscles around the upper lip. This can allow the upper lip to roll slightly outward, making more of the natural pink part of the lip visible.
Does a lip flip make your lips bigger?
A lip flip does not add volume to the lips.
Instead, it can make the lips appear slightly fuller because more of the natural lip becomes visible.
How is a lip flip different from lip filler?
A lip flip changes muscle activity around the upper lip. Dermal filler adds volume to the lip itself and can also be used to alter shape and definition.
How long does a lip flip last?
Most patients can expect the effect to last around 8–12 weeks, although individual results vary.
How quickly does a lip flip work?
The effect develops gradually. Patients may begin to notice a change after approximately 5–7 days, with the result becoming more apparent over the following two weeks.
What happens if I don’t like my lip flip?
The effect is temporary and will gradually wear off as muscle activity returns.
If you are concerned about your result or notice an unexpected change, contact the clinician who performed your treatment so that they can assess you and advise you appropriately.
Can a lip flip affect my smile?
Because the treatment deliberately changes muscle activity around the mouth, it can temporarily affect how the upper lip moves in some people.
This is why careful assessment and precise treatment are important.
Can I have a lip flip if I have had lip filler?
Previous lip filler does not automatically mean that you cannot have a lip flip.
However, previous treatments should be taken into account when your lips are assessed. The best approach depends on your current anatomy, the way your lips move and what you want to achieve.
Is a lip flip painful?
The treatment involves small injections around the upper lip. Most patients tolerate the procedure well, although you may feel brief pinching or discomfort at the injection points.
How much does a lip flip cost in Dublin?
Treatment costs vary between clinics and according to the treatment being provided.
At Castleknock Cosmetic Clinic, our current pricing is available on our cosmetic injection price list. We recommend confirming the current price when arranging your consultation, as prices can change.
A Lip Flip Is About Subtle Change, Not Bigger Lips
A lip flip with botulinum toxin can be a useful option for someone looking for a subtle change to the appearance of their upper lip without adding volume.
However, it is not the right treatment for everyone.
Understanding the difference between lip movement and lip volume is the first step. From there, an assessment can help determine whether a lip flip, dermal filler, another treatment, or no treatment is the most appropriate option.
For me, like any qualified medical practitioner, the goal is never simply to perform a treatment because someone has asked for it.
The goal is to understand what you would like to change and then decide whether there is a safe and sensible way to achieve that change.
At Castleknock Cosmetic Clinic, I assess your individual lip anatomy, proportions and movement before recommending treatment. If you are considering a lip flip in Dublin, a consultation gives you the opportunity to ask questions, discuss your expectations and understand which option is most appropriate for you.
Medically reviewed by Dr Hazem Kahlout, Medical Director, Castleknock Cosmetic Clinic. Dr Kahlout has practised aesthetic medicine since 1998 and is registered with the Medical Council of Ireland.
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