Smile lines filler is usually a hyaluronic acid gel injected into or beside the nasolabial fold, or into the cheek above it, to soften the crease. Results show immediately, and one approved product kept 88% of patients improved at 24 weeks, typically lasting nine months to a year. Bruising and swelling usually settle within a week.
This guide is part of our smile lines overview, which explains why folds form.
How filler works
Hyaluronic acid filler adds volume under the fold or restores cheek support, so the crease looks shallower; the body slowly breaks it down.
The US Food and Drug Administration (FDA) regulates dermal fillers as medical devices. Absorbable fillers are approved for moderate to severe facial wrinkles and folds, including nasolabial folds, in adults 22 and over. A 2024 network meta-analysis of 13 randomised trials concluded that hyaluronic acid (HA) is a safe filler for these folds and found HA caused fewer nodules than bovine collagen.
Your injector may place filler in one of two areas:
- Fold: a softer gel directly under the crease.
- Cheek: a firmer gel higher up to lift sagging tissue, which a consultant plastic surgeon at Nuffield Health (UK) describes for more pronounced folds.
The same surgeon advises “less is more.” In my practice, I place most of the volume in the cheek and use only a small amount in the fold itself, which keeps the smile natural.
Before and after
Smile lines filler before and after photos should show a softer, shallower fold, not a flat one, with a natural smile and no ridge.
| What to check | Good result | Warning sign |
|---|---|---|
| Fold depth | Shallower, still present | Completely flat or puffy |
| Smile | Moves naturally | Bulge beside the nose when smiling |
| Mid-face | Balanced | Heavy, wide cheeks |
| Photo timing | Two or more weeks after treatment | Taken the same day, with swelling |
When looking at smile lines before and after images, check that lighting and angle match. Before after shots taken the same day can overstate the result because swelling fills the fold. Side effects in the main product study were common but mostly mild and lasted seven days or less: redness 93%, tenderness 90%, swelling 86% and bruising 59%.
Juvederm and other brands
Several hyaluronic acid brands are approved for nasolabial folds; results depend more on the injector’s skill than the brand name.
For Juvederm before and after smile lines data, the patient labelling for JUVÉDERM Ultra XC describes a US study of 146 people, each with the product in one fold and an older collagen filler in the other. At 24 weeks, 88% maintained improvement with the HA side versus 36% with collagen. Of 48 patients who returned after more than 36 weeks, 75% still had improvement.
The meta-analysis found that poly-L-lactic acid, a collagen-stimulating filler, also “showed potential.” Non-absorbable fillers are FDA-approved for nasolabial folds, but Nuffield Health’s surgeon warns permanent fillers are much more likely to cause complications. The 2023 US average physician fee was $715 for HA fillers and $901 for non-HA fillers, according to the American Society of Plastic Surgeons (ASPS, US).
Safety
Accidental injection into a blood vessel is rare but can cause skin damage, blindness or stroke, according to the product labelling. A 2024 anatomy review notes the facial artery runs along or crosses the fold in more than 70% of Koreans studied. Seek urgent care for vision changes, white skin or unusual pain during or after treatment. For other injectable options across the face, see our facial rejuvenation guide.
Filler vs fat grafting
For deep smile lines around mouth, filler vs fat grafting is a trade-off between quick, adjustable results and longer-lasting but less predictable volume.
| Factor | Hyaluronic acid filler | Fat grafting |
|---|---|---|
| Procedure | Injections, minutes | Liposuction plus injection |
| Cost (US) | Average $715 (2023) | $3,000 to $5,500 (2024 range, facial) |
| Downtime | Days | Swelling and bruising, often weeks |
| Duration | About 9 to 12 months | Variable; some fat reabsorbs |
| Reversible | Yes, can be dissolved | No |
A small 2015 study of nine patients found fat injected into the fold reduced it immediately, then the correction gradually faded over six months. With fat alone, swelling affected 77.8% and bruising 55.6%. If sagging is the main cause, filler and fat both have limits; see our smile lines treatment comparison.
Frequently Asked Questions
FAQ
Answers on how long smile lines filler lasts, cost, pain, dissolving filler and deep folds where fat grafting may help.
How long does smile lines filler last?
Usually about nine months to a year for hyaluronic acid filler, according to one product’s labelling. In its main study, 75% of patients who returned after more than 36 weeks still had improvement. Duration varies with the product, amount and your metabolism.
How much does filler for smile lines cost?
The 2023 ASPS average physician fee was $715 per HA filler treatment, and $901 for non-HA fillers. Folds often need more than one syringe, and prices vary by country, clinic and injector experience.
Does filler for smile lines hurt?
Most HA fillers contain a local anaesthetic, so discomfort is usually mild. Tenderness afterward is common; 90% reported it in one product study, mostly lasting a week or less. A numbing cream can help before treatment.
Is filler or fat grafting better for deep smile lines around the mouth?
Filler is quicker, cheaper per session and reversible. Fat grafting uses your own tissue and may last longer, but it needs liposuction, more downtime and some fat is reabsorbed. For deep, sagging folds, a lift may suit better than either.
Can smile lines filler be reversed?
Hyaluronic acid filler can be dissolved with an enzyme called hyaluronidase, which is also used in emergencies such as blocked blood vessels. Non-absorbable fillers and fat can’t be dissolved, which is one reason doctors prefer HA.
If you’d like an assessment of whether filler suits your folds, you can book a consultation with Metropole Clinic by ABmedi. For causes and other options, return to the smile lines hub.
This article is for general education and does not replace a personal medical consultation.
References
Show sources
- About JUVÉDERM Ultra XC for Facial Wrinkles and Folds. Patient labeling. AbbVie. 2023. rxabbvie.com
- Dermal Fillers (Soft Tissue Fillers). US Food and Drug Administration. fda.gov
- Li MY, Chien WY, Kang YN, et al. Efficacy and Safety of Fillers for the Treatment of Nasolabial Folds: A Network Meta-Analysis of Randomized Controlled Trials. Aesthetic Plast Surg. 2024. link.springer.com
- Nose to mouth lines: How to correct smile lines both surgically and non-surgically. Nuffield Health. 2026. nuffieldhealth.com
- Hong GW, Song S, Park SY, et al. Why Do Nasolabial Folds Appear? Exploring the Anatomical Perspectives and the Role of Thread-Based Interventions. Diagnostics. 2024;14(7):716. mdpi.com
- Ghasemi B, Tabaie SM, Azizjalali M, et al. Injection of Autologous Fat Alone and in Combination With Autologous Platelet Gel for Nasolabial Fold Augmentation. J Skin Stem Cell. 2015;2(3):e35681. brieflands.com
- 2023 Cosmetic Procedures: Average Cost. American Society of Plastic Surgeons (ASPS, US). 2024. plasticsurgery.org
- 2024 Cosmetic Procedures: Average Cost. ASPS. 2025. plasticsurgery.org
