Do Fillers Work on Smile Lines?
Smile lines or nasolabial folds, if you want the clinical term, are the creases that run from the sides of the nose down to the corners of the mouth. Almost everyone has them to some degree. But as volume loss, gravity, and skin laxity progress with age, they can deepen significantly, making the face look tired, drawn, or older than it should.
So can filler fix them? Yes, but the best approach might not be what you'd expect.
Why Smile Lines Form
Nasolabial folds aren't just wrinkles. They're a symptom of structural change happening higher up the face.
As you age, the fat pads in the midface, the ones that sit over the cheekbones and give the cheeks their fullness, deflate and migrate downward. At the same time, you lose bone density in the cheek area, so the scaffolding that supports the soft tissue above literally shrinks. The skin and tissue that used to sit high on the cheekbone slides south, bunching up along the nasolabial fold and making it deeper.
On top of that, the skin around the mouth is under constant mechanical stress. Every time you smile, talk, or eat, this area folds and creases. Over decades, the combination of repetitive movement and loss of underlying support turns a natural expression line into a permanent groove.
Understanding this matters, because it changes how you should think about treating them.
The Problem With Filling the Fold Directly
The most obvious approach, and the one many patients ask for, is to inject filler directly into the nasolabial fold to plump it out. This does work. Filler placed along the fold can soften its depth and smooth the crease, and the result is immediately visible.
But here's the catch: if you only treat the fold, you're treating the symptom without addressing the cause. The fold is deep because the cheek above it has lost volume and dropped. If you keep filling the fold without restoring that lost support, you can end up with a heavy, flattened look around the mouth, the tissue gets bulkier but the face doesn't actually look younger or more lifted.
This is why experienced practitioners often recommend treating the cheeks first, or instead of treating the fold directly. Restoring volume at the cheekbone lifts the tissue above the nasolabial fold, which pulls it shallower from above. The result looks more natural, more lifted, and more rejuvenating than filling the line itself, because you're reversing the cause, not masking the effect.
In many cases, cheek filler alone is enough to improve the nasolabial folds to the point where no direct treatment of the fold is needed. In others, a combination of cheek support plus a small amount of filler in the fold gives the best result. This is something that should be assessed on a face-by-face basis during your consultation.
When Filling the Fold Directly Makes Sense
There are situations where treating the nasolabial fold directly is the right call. If the folds are deep but the midface still has reasonable volume and projection, direct filler can be very effective. Some patients have naturally prominent folds regardless of age, it's just part of their anatomy — and in those cases, softening the crease with a small amount of filler is straightforward and gives a great result.
It's also appropriate as part of a combined treatment plan. For patients with both midface volume loss and deep folds, treating the cheeks for lift and adding a touch of filler to the fold itself can deliver a more complete result than either approach alone.
The key is that the decision should be made based on what your face actually needs, not based on where you've been pointing in the mirror. A skilled practitioner will assess the full picture and explain why they're recommending a particular approach.
What the Treatment Involves
Whether you're having filler placed in the cheeks, the nasolabial folds, or both, the procedure is quick and straightforward. The area is numbed with a topical anaesthetic, and a hyaluronic acid filler is injected using either a needle or a cannula.
Treatment of the nasolabial folds themselves typically takes around 15 to 20 minutes. If cheeks are being treated at the same session, you're looking at around 30 to 45 minutes in total.
Results are visible immediately, though mild swelling for the first few days can temporarily exaggerate things. The settled result is usually apparent after about two weeks.
How Long Do Results Last?
Filler in the nasolabial fold area typically lasts between 9 and 18 months, depending on the product used and individual factors like metabolism and how much movement the area gets. The nasolabial folds are a high-movement zone, you use these muscles constantly, so filler tends to break down slightly faster here than in areas like the cheeks or jawline.
Cheek filler, by comparison, often lasts 12 to 24 months because it sits in a more stable, lower-movement area. This is another practical reason why addressing the cheeks as part of the treatment plan makes sense, you get longer-lasting structural improvement alongside any direct fold treatment.
A Note on Filler Type
At Karwal Aesthetics, we use hyaluronic acid fillers exclusively. While other filler types exist, calcium hydroxylapatite, poly-L-lactic acid, and others — hyaluronic acid offers a combination of safety, effectiveness, and reversibility that we believe is the gold standard.
The reversibility point is particularly important. If you're unhappy with a result or if a complication arises, hyaluronic acid filler can be dissolved quickly using hyaluronidase. Non-HA fillers cannot. For an area as prominent and expressive as the nasolabial region, we think that safety net matters.
Different HA fillers have different properties — some are softer and more fluid, others are firmer and more structural. The product chosen for your treatment will depend on the depth of the fold, whether we're also treating the cheeks, and what kind of result we're aiming for. This is all discussed and decided during your consultation.
The Bottom Line
Filler can absolutely improve smile lines, but how you treat them matters as much as whether you treat them. The best results come from understanding why the folds have deepened and choosing an approach that addresses the underlying cause, not just the visible crease.
Sometimes that means cheek filler. Sometimes it means treating the folds directly. Often it means a combination. The right answer depends entirely on your face, your anatomy, and your goals.
If your nasolabial folds are bothering you and you want a clear, honest assessment of the best way to treat them, book a consultation with Dr Arun Karwal at our Mayfair clinic.
