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January 27, 2026
Dr Tim Pearce
It is all the rage it seems, but do you know the difference between a ‘lip flip’ procedure and injecting dermal fillers into the lips for cosmetic enhancement?
In this blog, Dr Tim Pearce will weigh up the pros and cons of both the lip flip procedure (which uses botulinum toxin) and lip enhancement with dermal fillers, covering the risks with each, and when their use would give the best results for your patients.
In this blog, Dr Tim Pearce will share some expert tips on how to appropriately perform an aesthetic analysis of lips so you can create a holistic 8D lip treatment design. This educational piece is based on content from the world’s first online lip training with interactive 3D anatomy and injection animation – introducing the 8D Lip Design training course.
What is a lip flip?
A ‘lip flip’ treatment aims to create a slight upward ‘flip’ of the top lip. The procedure involves injecting the orbicularis oris muscle with botulinum toxin which has two effects – one, it relaxes the treated area and, two, it sometimes increases the resting tone of nearby untreated areas. Dr Tim believes that this is at the heart of the thinking behind the benefits of the procedure.
The orbicularis oris can be injected (with botulinum toxin) in two areas – the pars peripheralis (larger peripheral part) and the pars marginalis (smaller marginal part) where the muscle inserts into the vermillion border. Depending on where you inject, you will probably achieve subtly different results.
Dr Tim’s theory about why it sometimes results in an increase in either lip projection or the widening of the lip is because of the two ways that botulinum toxin works. If you are injecting the pars marginalis, the margin of the muscle, it relaxes that area if you have some hypertonic resting fibres; even if it is only slight, you should get some widening of the lip.
The extra element that may occur is when you have some increased resting tone in the pars peripheralis. If you have injected the marginal part of the muscle, so that means you get slight contractility above, and the relaxed muscle below, meaning that you are slightly pouting. Dr Tim does not think this is a very powerful effect, but it does have an effect, and is much cheaper than a syringe of dermal filler as you only require approximately four units of botulinum toxin to achieve a small difference and a patient who is happy until the effect wears off again.
Is lip flip a replacement for lip fillers?
Dr Tim believes that the lip flip procedure is not a replacement for injecting the lips with dermal fillers as it is not doing the same thing – the result is subtle and might help give a patient a flavour of what it is like to have fuller lips, but you are not adding volume to the lip.
With the lip flip procedure, the aim is to relax muscle, causing the lip to look slightly fuller. It is likely to lasts for two to three months at a time. Unlike with fillers, you cannot keep treating and adding more to get a bigger result or you end up with a floppy top lip and an inability to say the letter ‘p’ properly, whistle, or drink through a straw due to the muscle relaxing effect of the neurotoxin. There are many patients who will claim that they do not care about such abilities, but Dr Tim cautions that as clinicians you really should not be paralysing a functional muscle that we need to communicate and consume fluids. Be prepared to defend that decision when patients are insistent that they want more because they love the result.
When would you use a lip flip procedure instead of dermal fillers?
Dr Tim might use botulinum toxin in the top lip in a patient whose budget was not reaching far enough for lip filler, or if they were phobic of having dermal filler (for fear of over treatment) and just wanted a small difference. He would also consider it as an option if the patient were allergic to dermal filler or could not bear the thought of the discomfort associated with that treatment.
Typically, it might be useful to use it in those patients who want a small difference, are phobic of over treatment, thus the lip flip result gives them a flavour of treatment outcomes. You might then expect them to return in six to nine months with more confidence in deciding to have other procedures which will achieve a better result, like dermal fillers.
Does the lip flip procedure work if you have already got filler in the lip?
If there is dermal filler present in the lip, depending on how much is still in place, the product will likely do something to prevent the muscle from contracting quite as much, according to Dr Tim. Therefore, it may already have achieved some of the benefits that you would see by treating with botulinum toxin. If there is little filler, you will likely see more benefit in the top lip than if there is a lot of filler in place, but you should see some benefit because the two injectables work in such different ways.
Can you perform a lip flip procedure on any type of lip?
Dr Tim believes the answer is no and cautions the use of the lip flip procedure in older patients, if they have lost a lot of the shape to their philtrum, if it is elongated, because it will further weaken that structure.
The lip flip procedure is best suited to patients who are 25-40 and who have relatively good structure to their lips. You can sometimes achieve a better result if the muscle is quite strong and when they have a shorter philtrum.
A lip flip may help those patients with thin lips, but Dr Tim does not believe it is a particularly good approach to treating them. You will see a benefit, especially if they have hypertonicity, but they would not be a good candidate selection for treatment and dermal fillers would be a better approach in such patients.
Can you perform a lip flip procedure on the lower lip?
You can certainly inject the lower lip with botulinum toxin, and it is often used to relax fine lines in the area by treating the orbicularis oris in the lower part of the lip. It has the same effects, relaxing the muscle, so potentially could increase the tonicity of the untreated areas of the muscle, achieving the same lip flip. However, most patients want a bigger top lip, especially females, as a dominant top lip is an attractive feature, thus it would be unusual to perform a lip flip on the lower lip.
Are there any long-term side effects of causing temporary paralysis to the orbicularis oris?
There should not be any long-term effects because if you stop treatment, all the movement returns. However, if you are maintaining that treatment for many years, there is the risk that you can create an unnatural appearance when you use too much botulinum toxin in the lower face.
Ensure you regularly check the facial movements of your patients when they are expressing themselves – it can be useful to ask them to video themselves so you can monitor this once a year and document – you are looking for anything that appears slightly odd, does not move in the right way, and may be linked to the prolonged use of botulinum toxin in the lower face.
Dermal filler versus lip flip risks
The lip flip involves injecting botulinum toxin in the lip using tiny doses, therefore, the worst risk is a functional abnormality – inability to speak or eat in the normal way. The low doses mean that it should not be so severe that a patient could not consumer fluid or food but could be noticeable to the point that the patient would not want to eat or drink in public. The loss of tonicity around the muscles causes a loss of control and a loss of communication, but as subtle, temporary functional problems associated with over treatment with botulinum toxin, which will resolve.
Dr Tim notes that he always thinks about side effects and complications in terms of the impact that they have on the patient, and this may not necessarily be simply the physical impact – an inability to whistle will not be a huge problem for many patients, unless you are a professional whistler! You should therefore consider the psychosocial problems that could be caused by the potential side effects from a lip flip.
Dermal filler has a much longer-term potential risk, the worst (and rarest) being a vascular occlusion they could go on to cause a necrotic injury. Filler is certainly riskier than botulinum toxin, but the corresponding results are better and longer lasting.
Each treatment has its place, with a different risk-reward equation – low risk/low reward for botulinum toxin and the lip flip and higher risk/higher reward for lip fillers – meaning that they are not competing, and are useful for different patients.
If you have any further questions about lip flip procedures or injecting dermal fillers in lips, you can find Dr Tim Pearce on Instagram.
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Aesthetics Mastery Show
Lip Flip vs Dermal Filler
In this episode, Dr Tim compares Lip Flip with BOTOX to Dermal Filler and explains when you should use each procedure to ensure the best result for your patients. Watch the full Aesthetics Mastery Show here.
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8D Lip Design
With all the conflicting advice out there about lip filler treatments – vertical or horizontal? needle or cannula? – it can be difficult to know how to inject to create the lips your patient desires.
If you are suffering from technique overwhelm, worrying about causing a vascular occlusion (VO), or panicking about injecting thin lips, then Dr Tim Pearce’s brand-new ultimate lip course is going to teach you the different techniques, anatomy, and skills you need to create medically beautiful lips.
Dr Tim Pearce eLearning
Dr Tim Pearce MBChB BSc (Hons) MRCGP founded his eLearning concept in 2016 in order to provide readily accessible BOTOX® and dermal filler online courses for fellow Medical Aesthetics practitioners. His objective was to raise standards within the industry – a principle which remains just as relevant today.
Our exclusive video-led courses are designed to build confidence, knowledge and technique at every stage, working from foundation level to advanced treatments and management of complications.
Thousands of delegates have benefited from the courses and we’re highly rated on Trustpilot. For more information or to discuss which course is right for you, please get in touch with our friendly team.
