Hyaluronic acid and frown lines : a possible indication
Hyaluronic acid is a molecule naturally present in the skin's extracellular matrix. Its exceptional ability to retain water and restore volume makes it a reference filler for treating static wrinkles.
Frown lines, however, are a particular case. They result not simply from skin laxity or age-related loss of support, but from a genuine skin crease caused by intense, repeated muscle contractions. Hyaluronic acid injections performed without considering the underlying muscular dynamics may therefore produce limited or even unattractive results.
Filling the glabella is therefore not a direct alternative to botulinum toxin. It is a complementary approach reserved for specific indications, generally when the crease persists despite neutralising muscle activity.
When are hyaluronic acid injections justified for frown lines ?
Hyaluronic acid has a place in frown line management primarily in two clearly defined situations :
- Patients with a deep static wrinkle : a persistent skin crease visible even without muscle contraction, despite previous botulinum toxin treatment. Muscle relaxation has neutralised the functional cause, but the dermal fold remains. Hyaluronic acid injections can then smooth and soften this residual mark.
- Patients unable to receive botulinum toxin for medical or personal reasons. Hyaluronic acid can then be used cautiously through superficial micro-injections strictly confined to the dermis to avoid complications associated with injections placed too deeply
In every case, glabellar filling requires rigorous dynamic assessment. Careful observation of facial expressions, both at rest and during movement, is essential to establish an appropriate, safe treatment plan.
The particular anatomy of the glabella
The glabella is one of the most vascularly sensitive facial areas. It is supplied by a particularly dense arterial network, including the supratrochlear and supraorbital arteries, some deep branches of which communicate directly with the ophthalmic circulation. This anatomy makes any injection potentially risky if the product is incorrectly positioned.
The main danger is vascular embolism : if hyaluronic acid is accidentally injected into a vessel, it may migrate and cause severe complications ranging from skin ischaemia to rare but serious visual damage.
For these reasons, filler treatment for frown lines is strictly reserved for experienced doctors who understand both vascular anatomy and safe injection techniques, such as cannula use and the blanching technique.
Which types of hyaluronic acid are used for frown lines ?
Product selection is decisive. Unlike deeper areas such as the nasolabial folds or temples, the glabella requires very fluid, lightly cross-linked hyaluronic acid to avoid overcorrection or visible nodules.
Manufacturers now offer formulations specifically designed to fill fine to moderately deep wrinkles, with excellent tissue tolerability. These gels gently correct the skin crease while respecting natural facial expression dynamics.
Conversely, an overly dense product or excessive volume risks creating an unattractive prominence or even a frozen appearance. Treatment success therefore depends equally on delicate technique and appropriate product selection.
How long do results last after filling frown lines ?
Hyaluronic acid injections into the glabella produce immediate results : the static wrinkle is visibly softened by the end of the session. The optimal effect is generally reached after a few days, once the product has integrated properly into the tissue.
Longevity depends on several factors : product type, wrinkle depth, residual muscle activity and skin quality. Results last an average of 6 to 10 months, sometimes longer when treatment is combined with botulinum toxin.
However, it is important to remember that hyaluronic acid does not treat the cause of the wrinkle, namely muscle contraction. Without underlying botulinum toxin treatment, the filling effect will inevitably be shorter-lived.
What do medical studies say about filling frown lines?
Scientific literature on hyaluronic acid injections for frown lines remains more limited than that on botulinum toxin, because the indication is less common and the treated area requires greater precautions. Nevertheless, several publications, particularly in Dermatologic Surgery and Aesthetic Surgery Journal, report good patient satisfaction when the procedure is performed by an experienced doctor.
These studies consistently emphasise prior assessment, careful product selection and technical injection expertise. In most cases, they also recommend a two-stage approach, with a review 15 days later for a touch-up if needed.
Hyaluronic acid alone or combined with botulinum toxin for frown lines ?
In the vast majority of cases, optimal treatment for frown lines combines both techniques :
- Botulinum toxin is injected first to inhibit the muscle contraction responsible for frown lines.
- Hyaluronic acid may then be injected 10 to 15 days later, only if the skin crease persists and the fold is sufficiently pronounced to justify filling.
This two-stage approach optimises the aesthetic result. It follows a cause-based treatment strategy : botulinum toxin treats the cause, while hyaluronic acid corrects the consequence.
Why can't some frown lines be treated with hyaluronic acid injections ?
Not every frown line is suitable for filling. When wrinkles are exclusively dynamic — visible only during muscle contraction — there is no skin crease to correct. Botulinum toxin is then the only appropriate treatment because it directly addresses muscular overactivity. Injecting hyaluronic acid into a purely dynamic wrinkle risks accentuating the fold or creating an unattractive ridge.
Hyaluronic acid filling should therefore be limited to deep static wrinkles that persist even after botulinum toxin treatment. Distinguishing dynamic from static wrinkles is central to the initial medical assessment, ensuring appropriate and safe aesthetic care.
Can hyaluronic acid cause specific complications in frown lines ?
Among facial areas, the glabella is considered one of the highest-risk sites for dermal filling because of its particularly vulnerable terminal vascular network. An injection placed too deeply or performed without prior aspiration may occlude an artery, causing skin ischaemia, localised necrosis or — in very rare but documented cases — visual damage through retrograde migration towards the ophthalmic artery.
Although rare, these complications justify restricting the procedure to expert doctors using appropriate equipment (microcannula, low-pressure syringe) in a medical setting able to provide immediate care in the event of a vascular incident.
Awareness of these risks explains why many doctors choose not to inject hyaluronic acid into the glabella without prior botulinum toxin treatment.
