Filler can create some of the most beautiful results in aesthetic medicine. It can also, in rare cases, make you go blind.
Both of those sentences are true, which is why this is a conversation worth having properly.
I have been injecting for over two decades, first at The Sloane Clinic and now at SW1 Clinic. In that time I have had the same three filler conversations more times than I can count.
Three patients who explain almost everything about filler
The first sits down and says she wants to look like she did five years ago. She has genuine volume loss: hollowed temples, flattened cheeks, lips that have lost their definition. Filler is the right tool. We replace a little of what time has taken, and she still looks like herself. That is filler at its best.
The second says she needs filler for her jawline. But she does not have volume loss. She has skin laxity. Her skin is sagging, not hollow. I explain that adding filler beneath loose skin tends to make the lower face heavier. Sometimes she listens. Sometimes she goes elsewhere, and comes back later looking unexpectedly substantial.
The third has had filler every year because she was told the last lot had disappeared. Her face has become gradually fuller, wider and less defined. She does not look older, exactly. She simply does not recognise herself in photographs.
The right product in the right place can be beautiful. The wrong product, the wrong diagnosis, or simply too much, can change a face entirely.
When filler genuinely works
Genuine volume loss. Ageing is not only wrinkles. The facial skeleton remodels, fat compartments shrink and shift, skin thins, support structures change. When volume has actually been lost, filler can replace some of it. Temple filler restores the frame of the upper face. Midface filler replaces lost contour. Carefully placed lip filler restores definition without creating an entirely new species of lip.
Proportional imbalance. Some people have not lost anything. They have a recessed chin, an asymmetry, proportions they would like balanced. A small amount of filler in the chin can transform a profile. This is where millimetres matter, and where you are not filling a space so much as changing how the whole face is read. The nose can sometimes be camouflaged this way, but it is also one of the highest-risk areas on the face, so it is not a casual lunchtime decision.
Support and contour. Strategically placed filler can restore architecture and may give a modest lifting effect. It does not retighten ligaments, remove excess skin, or reproduce a facelift. It can improve the architecture. It cannot suspend disbelief indefinitely.
When filler is the wrong tool
Significant skin laxity. You do not fix a sagging ceiling by stuffing more insulation into the attic. I have seen patients given large volumes of cheek and jawline filler to lift their jowls. It did not lift them. It made the lower face larger. If laxity is the real problem, the honest conversation involves energy-based tightening, collagen-stimulating treatments or surgery, depending on severity.
Festoons and malar bags. The under-eye is the most technically demanding area on the face. A genuine tear-trough hollow, treated conservatively, can look beautiful. But a hollow is not a bag. If you have malar oedema or festoons, filler attracts water and the puffiness becomes more noticeable. One patient put it perfectly: she wanted to look less tired, and now she looked tired and puffy. The hollow had improved. The bag had become the main character.
Wanting a facelift without having a facelift. I understand the wish entirely. Surgery has cost, downtime and risk. But repeatedly adding filler to a face that needs tissue repositioning produces a very particular result: wider, less defined, every hollow filled until the peaks and valleys disappear. A beautiful face has light and shadow. Fill every shadow and you do not create youth. You create more face. I have written about that trade-off separately.
When filler goes wrong
Everything above is an aesthetic problem. Expensive, sometimes distressing, rarely dangerous. What follows is different, and it is the reason filler is a medical procedure rather than a beauty treatment with a needle attached.
Vascular occlusion. Filler injected into a blood vessel obstructs blood flow. If that vessel supplies skin, the skin can become ischaemic and, without prompt treatment, tissue can die. If filler enters a vascular pathway connected to the ophthalmic circulation, it can cause sudden and sometimes permanent vision loss. The nose, glabella, forehead and nasolabial region have all been implicated in published cases (Beleznay K et al. Dermatol Surg. 2015;41:1097-1117). Vision loss is rare. Rare is not the same as impossible.
This is why your injector needs more than a steady hand and an attractive Instagram page. They need detailed anatomical knowledge, an emergency protocol, and hyaluronidase within reach every single time they inject hyaluronic acid.
I inject slowly, at low pressure, in controlled amounts, and choose needle or cannula according to the anatomy, the product and the plane. Cannulas appear to reduce the risk of vascular occlusion in some circumstances, but they do not eliminate it (Alam M et al. JAMA Dermatol. 2021;157:174-180). Neither does a negative aspiration (Goodman GJ et al. Aesthet Surg J. 2021). There is no technique that makes filler risk-free.
Delayed nodules. Complications do not always arrive on the day. Weeks or months later, patients can develop lumps, swelling or inflammatory nodules, from product placement, infection, immune-mediated inflammation or foreign-body reaction. Some settle with treatment. Others are stubborn. A delayed lump deserves a diagnosis, not more injections aimed at it.
Filler can last far longer than advertised. This is the part patients are rarely told clearly. A 2024 review of MRI scans from 33 selected patients who had midface hyaluronic acid filler found it still detectable more than two years after injection in every one of them, and in one case up to fifteen years later (Master M et al. Plast Reconstr Surg Glob Open. 2024;12). That was a small, selected group, so it does not mean every filler lasts fifteen years. It does mean we should stop assuming that last year’s filler has politely disappeared.
I have met patients who started filler in their thirties and received automatic yearly top-ups, with nobody reassessing the whole face. The solution is not to panic and dissolve everybody. The solution is to stop treating filler like an annual subscription.
Four principles
Diagnose before injecting. I begin with the problem, not the product. Is it volume loss, laxity, muscle activity, pigment, bone structure, fluid? Each wants a different strategy. If someone recommends a syringe before examining your face, taking a history and explaining a plan, leave. Preferably before the card machine appears.
Begin conservatively. You can always add more. Correcting too much is harder. Hyaluronidase dissolves hyaluronic acid filler, but it is not an undo button: different fillers respond differently, more than one session may be needed, and it can cause swelling, bruising and, rarely, allergic reactions (Jung H. Arch Plast Surg. 2020;47:297-300).
Treat the face, not the calendar. Before adding more, assess what is still there and how the face has changed. Sometimes the answer is a tiny adjustment. Sometimes it is to wait. Sometimes it is to dissolve. Sometimes it is to stop touching the face.
Preserve facial identity. The objective is not a higher cheek, a sharper jaw and a bigger lip on everybody. Good filler does not announce itself from across the room. People should notice you, not your injector.
Sometimes the right amount is none
I once saw a woman in her twenties with full cheeks, balanced features and lovely skin. She wanted filler because her friends were having it. I told her she did not need any. Wear sunscreen, use evidence-based skincare, enjoy your face, and come back when there is actually something worth treating.
I have also treated patients for years and eventually said: we need to stop adding, let us wait and reassess. Doing nothing is an underrated procedure. In an industry built on doing more, restraint is not a lack of skill. Restraint is part of the skill.
Filler is not good or bad. It is a tool. In the right hands, for the right diagnosis, it is superb. Used for the wrong problem, or in excessive amounts, it is disappointing, expensive and occasionally dangerous. The best injector is not the one who can place the most filler. It is the one who knows when not to inject.
Watch or listen to the full episode
I go through all of it, with the studies, in this episode of The Chai Files.
Prefer to listen? The audio version is here.
If you would like your own face assessed properly, before anyone reaches for a syringe, my team and I see patients at SW1 Clinic in Singapore, and you can book a consultation here.
This article is general education and does not replace an individual medical consultation. All procedures carry risks. Patient stories are anonymised composites.
Get these in your inbox. I write a free newsletter on ageing well, on the treatments that earn their place and the ones that do not. Subscribe here.