McKeown Medical
202 W George St, Glasgow, G2 2PQ
Date posted — 19.04.24
Dermal fillers are one of the most powerful tools we have to create a more youthful appearance. As we age, our faces lose volume – both from reabsorption of fat and bone – which creates a hollow, sunken appearance, that allows the soft tissues of the face to droop. Dermal filler injections allow us to correct that with a relatively quick and easy treatment, which is what makes them such popular cosmetic treatments. One of the most obvious questions people ask is ‘how long do fillers last’, which feels like it should have an simple and straight forward answer. If you go with the answer that the filler manufacturers tell you then, depending on the type of filler used, the answer is up to two years. But a fuller answer is more complicated than that, which is what I want to explain in this blog.
I’m sorry to bore you with a topic like history, but I promise it is relevant to understanding the answer properly. When the first generation of fillers appeared on the market in the early 1980s they were made from bovine collagen – collagen that was taken from cow hide. Because our body recognised the collagen as foreign material it mounted an immune reaction to remove it, which typically took around 2 – 4 months to eliminate the foreign collagen. So the effects of the collagen typically lasted around 2 – 4 months. Because of the immune mechanism by which collagen products were removed, around 5% of patients had a allergic reaction to the product which meant that everyone had to get a patch test done before having the treatment – which was more expensive and time consuming for everyone.
In the mid-90s a Swedish company came up with the idea of using hyaluronic acid as a filler material. They made the hyaluronic acid from a non-animal source by genetically modifying streptococcus bacteria to produce hyaluronic acid that was genetically identical to human hyaluronic acid. Because it was genetically identical to our body’s own hyaluronic acid, it solved the problem of allergic reaction which meant they had a superior product that did not require a test patch like collagen. They also noticed that hyaluronic acid appeared to last longer than collagen, although that was something that was never really properly studied.
In the early clinical trials they compared the longevity of hyaluronic acid fillers with the longevity of collagen products and, perhaps unsurprisingly, the hyaluronic acid products lasted longer. They would do studies for six to nine months and at the end of that period of time they would say ‘hey, look, the hyaluronic acid is still there at six months but the collagen was gone at three months’. And so it became accepted that hyaluronic acid lasted six months. Later there were more studies that looked at up to a year, then 18 months and finally two years. What researchers have never done however is keep following those patients up to see when the filler actually went away. They just get to the end of the study period and say ‘hey, patients still have filler so this is now how long it lasts’. They also assessed the outcome using photographs of patients, which is a pretty subjective tool.
Now, we are seeing more and more anecdotal evidence from MRI scans of fillers lasting much longer than expected – often years and years after the first injection. This is not a bad thing: in fact, it means that the hyaluronic acid dermal fillers are much more efficient and cost effective than we previously thought. However, it’s important to really understand this so we do not over treat and cause the dreaded unnatural, overfilled appearance.
Hyaluronic acid is a molecule that we all have present in our skin and in connective tissue. It’s especially prevalent in our eyes and in our joints and we have some in our skin too. Our body has this habit of breaking down material to replace it with new material – and hyaluronic acid is one of the molecules that does that. It gets broken down by an enzyme called hyaluronidase, which turns it into small sugar molecules – known as monosaccharides – which get absorbed and expelled from the body via the lymphatic system. Our assumption is that hyaluronic acid fillers get broken down by excess hyaluronidase that our body produces naturally anyway. Except, most of the fillers we inject are injected into the fat below the skin – and there is not a whole lot of hyaluronic acid, nor hyaluronidase present naturally there. So how does the filler get broken down? Well that’s a really good question that none of us really completely understand yet.
I’ve been injecting hyaluronic acid fillers for almost two decades now. In our practice, we inject around 5000 – 6000 fillers per year. We have a lot of experience, and we have seen a lot. And one of the things that I’ve seen is that my patients need top up injections much less frequently that expected. In the early days of dermal fillers we used to perform very basic techniques – simply injecting one syringe at a time and the patient would come back every six months and we would do another one syringe. What we were doing back then was under treating, which is why when patients came back every six months we could keep doing more and it would look ok – to a point. I call that point ‘optimal correction’. When you reach the stage of optimal correction, if you keep treating every six months you get the over-filled face. And that is one of the key reasons you see so many people who look over-filled – they got into the habit of doing regular treatments that initially looked good, but they kept going beyond the point of ‘optimal correction’ and got a build up of product that eventually took them to an unnatural place.
You might think ‘well why didn’t they just stop when it got too much’. The answer is that it is very difficult to be objective about your own appearance and because it happens gradually over time, most patients don’t notice that gradual creep from natural to unnatural. That’s why it’s so important that you find a good doctor you trust to keep you away from that point.
Nowadays our understanding of the ageing process is much more sophisticated than it was 20 years ago. We understand the anatomy of the fat and bones much better, and particularly how they change with age and so we can create much more effective filler treatment strategies that don’t just focus on lines and wrinkles but actually look at the changing shape of the face with age. This means that our filler treatments are much more effective. If you are in your 50s and your face has been losing volume for the best part of 30 years, then you are going to need more like 10 to 20mls of filler to reach optimal correction rather than 1 or 2mls. But when you achieve that optimal correction, you need to take your foot off the gas and re-fill very slowly in the future.
For most of my patients who have had had an optimal correction, I don’t see them back (unless they come in for other skin treatments) for 18 – 24 months. At that stage, we use much smaller volumes to simply maintain them where they are.
The amount of filler injected does have an impact on the longevity of the filler. If you inject a very small amount, and spread it over a wide area, then filler seems to break down more quickly.
There are now a couple of calcium hydroxylapatite filler products on the market. Radiesse, which is calcium hydroxylapatite in a collagen carrier and Harmonica, which is calcium hydroxylapatite in a hyaluonric acid carrier. The advantage of these products is that the calcium hydroxyapatite component causes an inflammatory response that will stimulate collagen production. This means that as well as having a filling effect, these products may also improve the quality of the overlying skin over time. Again, it is said that these products last ‘up to two years’ although this is a bit vague, and there is no concrete answer and so my advise to patients is to review the outcome in 18 – 24 months and decide then what, if any, additional treatment could be helpful. I mainly use these products for lifting the cheeks and jawline, especially when there is skin quality issues and the patient doesn’t want to have laser skin rejuvenation.
Poly-L-Lactic acid is the material that some dissolving stitches are made from. It also causes an inflammatory response that stimulates collagen production, which is the mechanism by which these products create volume. These are promoted as a ‘more natural’ way of adding volume to the face, because it stimulates your own collagen. However, that’s a bit of a marketing gimmick. The biggest issue with these products is that they have a tendency to form lumps. In one large case series, carried out by a very skilled and experienced dermatologist, one in five patients developed lumps or nodules. One in 10 patients had lumps that were visible. One in 100 patients required surgical excision of the lumps. In comparison to other types of dermal fillers used in the face, this is quite a high rate of complication and is the reason we don’t use this in our practice. (Poly-L-Lactic acid might be more useful in other parts of the body). Again, the expected duration of Poly-L-Lactic acid is up to two years, but this is also based on poor evidence and I’ve seen it persist much longer.
The cheek is one of the most prominent parts of the face to lose volume with age. There is often a lot of focus on the front of the cheek, or the apple of the cheek, when injecting fillers. This is important for some patients, but not all patients. When we assess the cheek we need to look at it both at rest and when smiling. Often the cheek can look hollow at rest, but full on smiling and if you add volume to the front of the cheek in this situation you will create a look that might look nice at rest, but over-filled and hamster like when the patient smiles. When restoring the cheek, we need to assess the whole cheek – which includes the front part of the cheek, the lower cheek and the back of the cheek (the part in front of the ear). When the cheek is restored properly with cheek fillers, the results can be a dramatically more youthful appearance that looks very natural – even on smiling – so long as the treatment plan takes account of the patients own unique anatomy.
Lip fillers are one of the most abused types of filler treatment that put a lot of people off the idea of having filler. The purpose of filler is to restore volume loss, or create additional volume in areas of deficiency. However, many people over-fill lips to create a ‘fashion’ look that looks unnatural. Again, lip fillers have a habit of lasting a long time. When we fill the lips, we typically don’t re-fill until at least 2 years after the treatment – and often it’s longer.
Under eye fillers are one of the most challenging treatments to perform. Loss of volume from around the eye is a key part of how the eye ages, so restoring volume here is important, but it’s easy to over do it. One of the key features of hyaluronic acid is that it loves water and draws in water from its environment, so it can expand a little over time. In most parts of the face, if this happens to a small extent it doesn’t really matter. But under the eye – where the skin and overlying soft tissues are very thin – even a little bit of expansion can be a problem that creates a puffy look under the eye. To avoid this, it’s always best to under correct slightly and spread repeat treatments out adequately – it’s usually at least two years between under eye filler treatment, and often much longer than this. This is another area that you really need to be careful not to over-correct.
Most side effects of filler injections are minor and self limiting, which means they go away on their own. The injection itself will inevitably cause a little bit of swelling and redness and it may cause some bruising which will go away like any normal bruise. Most patients are able to resume normal activities immediately following treatment. If some bruising develops, you can begin using make up to hide it from the day after treatment.
The most common side effect is called a delayed inflammatory reaction. This happens to about 1 in 1000 filler treatments. This usually happens a number of months following the initial treatment. The filler has already settled and most patients have forgotten about the treatment by this time. Then, suddenly, the immune system decides that it doesn’t like the filler any more and causes it to turn hard and lumpy. No one truly understands why this happens, although there are lots of theories on it. If it happens, occasionally it settles itself down within a couple of days without any treatment. If it doesn’t self resolve, then we need to go ahead and dissolve the filler by injecting an enzyme that breaks it down. Sometimes we need to also prescribe steroids to reduce the inflammation. Although this can be a distressing experience, it is treatable although you are at higher risk of this happening again with future treatments if you chose to carry on with more filler treatments in the future.
The most serious side effects of filler injections are caused by inadvertently injecting filler into a facial artery. If this happens, the filler can block the blood supply to the tissues which means nutrients don’t get to the skin and can ultimately result in some of the skin dying – or undergoing a process of necrosis, resulting in permanent scarring. This is a rare side effect, estimated to happen at a rate of around 1 in 100,000. There are a number of steps that we take during the injection process to minimise the chances of this happening: avoiding areas where we know important blood vessels should be, using blunt cannulas where possible and aspirating before injection. Even if all of these safety checks fail, if you see the blockage immediately and treat it quickly by dissolving the filler you should be able to avoid it progressing to leave a long term problem. We have never had a case of necrosis in our practice.
Even more rarely, if you get filler into an artery, instead of flowing forward to cause necrosis it can move backward in the circulation and block the blood supply to the eye – causing vision loss. This is the most devastating complication from dermal filler treatments. Fortunately, it is extremely rare. There has only been one reported case in the UK from 2012. The doctor involved in that case has spoken openly about what happened, and it seems the problem was caused by using an unusually large sharp needle that wouldn’t be considered standard practice. Most of the cases of vision loss that have been reported around the world seem to come from East Asian countries, which may be due to either anatomic variations that are common in that part of the world or different techniques that are used there. This is the sort of complication that most doctors hope to never see once in their lifetime.
You have two options for reversal of hyaluronic acid filler. The first is to wait for the filler to break down naturally. This can take a long time, and could easily be a number of years. If you are not satisfied with the outcome of your filler treatment, or if you have a complication, you can dissolve the filler by injecting hyaluronidase which is an enzyme that breaks hyaluronic acid down. The preparations of hyaluronidase that are available are not licensed for use in breaking down fillers, but it is commonly performed on an ‘off-label’ basis. Sometimes you need multiple sessions of hyaluronidase to dissolve the filler, especially with the newer filler materials that are more cross linked and designed to last longer – they are harder to break down. But dissolving injections still offers you a faster way to get rid of the product than waiting for it to happen naturally. The hyaluronidase injections can cause some swelling and allergy is possible, so not everyone is suitable for repeat treatments.
How long do fillers last seems like it should be an easy question to answer, but unfortunately the science is a little more complicated. They key in all of this is finding a reputable doctor who not only performs technically excellent injections, but you can trust to give you solid advice on your own circumstances and how to get the most out of the treatment without pushing it too far. Although volume loss is an important part of the ageing process, it’s not the only part and not every sign of ageing can be corrected with filler injections. The advice of a good doctor is key to achieving the best outcome.
As the filler starts to wear off, the signs of volume loss begin to reoccur. Many people are worried that their skin may sag more because it’s been stretched by the filler. This should never happen, because the filler should only be used to restore what’s been lost rather than stretching the skin beyond where it was originally. As long as you adhere to this principle of restoration you should never have a problem as the filler goes away.
Fillers last longer than most people expect. If you chose to have your filler treatments performed in stages then you may go back regularly for top up treatments until you reach the point of ‘optimal correction’. When you achieve optimal correction however, they should be touched up very infrequently. It’s rare to do a touch up treatment in less than 18 months, and most patients are every 2 years or more.
It’s impossible to say that filler ever goes away fully. In most cases yes, it does, eventually – but over a much longer period of time that most people expect. The process of filler break down happens much slower than doctors originally thought. If you do not like the results of your filler treatment, then instead of waiting for it to break down naturally, you may want to think about some dissolving injections to break the product down.
Yes, fillers generally last much longer than Botox. Botox is a drug that works by relaxing muscles. It typically wears off within 3 – 6 months. Filler injections with modern hyaluronic acid fillers are licensed to last up to a couple of years, although they often persist even longer than this.
Yes, fillers can stay in your face for years. In fact, filler persisting for years is the norm in most cases. Some hyaluronic acids fillers are licensed to last up to two years now, although it often persists for even longer than this.
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You know we like to look after our team at McKeown Medical! This is our clinic nurse, Therese, who many of you will know if you`ve had surgery or laser at the clinic.
Therese was unhappy with her lower face and neck. When you look at her face, however, a major contributing factor to her unhappiness with the appearance of her neck was the lack of projection at her chin. The very talented Dr Rhona treated this for her using some filler to improve the projection of her chin and definition of her jawline. This is her before and immediately after.
She is gorgeous both before and after, but notice how much better her lower face and neck looks with the subtle improvements to the chin and jaw?
Because good skin is always in! As summer draws to a close here is a little reminder of what matters when it comes to looking after your skin from our very fabulous medical director, Dr Rhona Cameron. What are your top tips?
We know we love a combination treatment! This patient came to us originally about the bags under her eyes which we addressed with some laser resurfacing and then some filler. We then came back a couple of weeks later and addressed the volume loss in the others areas of the face including the cheeks, chin and jowls.
She is a few weeks after her treatment now and delighted with her outcome. What do you think?
Upper eyelid surgery is one of the most popular procedures we perform in the clinic. Although it`s a simple procedure that essentially involves removing a small amount of skin fat and muscle above the eyes, making the decision about how much of what to remove - and how much to leave behind - is an art, and one that varies considerably from surgeon to surgeon. @bramhallplasticsurgery is our resident eyelid expert. Here`s a little video of him explaining how he approaches eyelid surgery to deliver beautiful, natural results that leave our patients looking fresh not frozen!
Crepey skin and fine lines under the eyes are one of the most common concerns patients talk to us about in the clinic. This area can`t always be improved using wrinkle relaxing injections or dermal filler as the problem is not always caused by volume loss.
When patients have this concern, the only way to get rid of it is with resurfacing. Although we normally do this as part of a full face resurfacing procedure, we can treat the eyelids in isolation for some patients - like this lovely lady. The rest of her skin was in good condition, so we just treated the fine lines under her eyes. She`s delighted with the results.
What do you think?
The volumetric facelift is one of the most popular procedures that we do in the clinic. It’s a signature part of our practice that we are best known for. It treats many of the underlying causes of facial ageing - loss of fat, reabsorption of bone - resulting in a rejuvenated, but natural appearance. Here’s a little video of our medical director Dr Rhona Cameron talking about it. What do you think?
The lower eyelid is one of the most complex areas of the face to improve. Most patients have a combination of problems under the eyes and so they need a combination of treatments to achieve the best result.
This patient had some volume loss, which was treated with some filler, but she also had some fine lines and loose skin which we treated with laser resurfacing. She is six weeks out from her treatment and already delighted with the results.
What do you think?
Not all lip aesthetics are about volume! Very often its the shape of the lip thats the issue, rather than volume. This patient had tried filler before but without achieving the outcome she wanted. She came to see the very talented @bramhallplasticsurgery who diagnosed the real issue - the length of her lip. Her performed a lip lift procedure to shorten the lip, which everted the red part of the and improve the promotions. The after photo is a couple of months later. The scar under the nose still looks a little red, but that will continue to fade as the months go by. She had no filler or any other volume added to her lip - just the lift.
She`s absolutely delighted with the results - what do you think?
Rejuvenating the lower eyelid varies much more from patient to patient than any other cosmetic concern. Surgical treatments have always had varying results, and we now understand that the anatomical changes that contribute to ageing of the lower lid are much more variable, so the right solution is much more complex and nuanced than the upper eyelid.
This patient`s main issues were fine lines, wrinkles and darkness as well as loss of volume in the mid-face. Performing a traditional surgical blepharoplasty for her would not have solved all of these issues, and could have made some of them worse. To treat her lower lids we first did some aggressive laser resurfacing - this removes the fine lines and wrinkles and tightens the skin. We then came back and restored volume to the mid-face, focusing on the junction between the lower eyelid and the cheek.
She is a couple of months out from her treatment and delighted with the results. What do you think?