Commentary on Efficacy and Safety of Hyaluronic Acid Lip Fillers: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
- 1 hour ago
- 4 min read
Introduction
Hyaluronic acid (HA) lip fillers represent one of the most widely performed procedures in aesthetic medicine today, with demand growing consistently over recent years.
Despite broad clinical experience, perceptions of efficacy and safety have often been shaped by empirical observation rather than robust quantitative data. Against this backdrop, the systematic review and meta-analysis by Wen et al. carries particular significance: by analyzing exclusively randomized controlled trials (RCTs), it provides the highest available level of evidence on this topic.
Key Findings
The meta-analysis shows that approximately 60% of patients achieve an improvement in lip fullness, while over 80% demonstrate overall aesthetic improvement and approximately 68% report satisfaction with treatment.
These findings highlight a clinically relevant observation: the aesthetic improvement perceived by both patients and blinded evaluators consistently exceeds the measurable volumetric gain alone. This suggests that treatment outcomes depend not solely on the quantity of product injected, but on a combination of factors including lip proportion, harmony, and integration within the overall facial context.
From a clinical standpoint, this evidence supports a treatment planning approach centred not on absolute volume, but on the overall aesthetic objective, personalised according to the patient's morphological characteristics.
Safety profile
The meta-analysis reports that approximately 50% of patients experience adverse events of any grade, while serious adverse events remain rare (approximately 1.1%). The most frequently reported side effects are swelling (78%), firmness (48%), bruising (34%), and injection-site tenderness (33%).
This finding warrants careful clinical reflection: adverse events are common, yet the vast majority are mild and self-limiting injection-site reactions. The rare occurrence of serious complications — such as angioedema, arterial compression ischaemia, or persistent nodule formation — underscores the need for adequate technical training and thorough pre-treatment patient counselling.
Clinically, this implies the importance of transparent communication with the patient: not minimising the likelihood of side effects, but clearly explaining their predictability, manageability, and typically transient nature.
Differences across filler technologies
The subgroup analysis suggests possible differences among available technologies. In particular, Vycross-based products (Juvederm Volbella) appear to be associated with lower rates of both total adverse events (32.49%) and serious adverse events (0.28%) compared to the other categories analysed.
However, it is essential to emphasise — as the authors themselves do — that these data derive from subgroups with limited sample sizes and are purely descriptive in nature. It is therefore not possible to draw definitive conclusions regarding the clinical superiority of one technology over another. Interpretation of these differences must account for the rheological characteristics of each product, injected volume, technique employed, and variability among injectors.
Study limitations
The study presents several methodological limitations, which the authors transparently acknowledge:
• High statistical heterogeneity across included studies (I² > 90% for most outcomes), limiting the robustness of pooled estimates.
• Variability in follow-up time points and assessment scales across trials: aesthetic improvement is frequently evaluated at 3 months post-treatment, which may overestimate results compared to longer-term follow-up.
• Non-uniform definition of serious adverse events across studies, with the risk of classification bias.
• Limited number of available RCTs for some filler technologies, precluding a robust direct comparison between products.
Clinical implications
In light of the evidence presented, several practical considerations can be drawn for the aesthetic medicine practitioner:
• HA lip filler is effective, but not uniformly so across all patients: approximately one-third of treated patients do not achieve the expected level of satisfaction, making expectation management during consultation a fundamental step.
• Aesthetic outcomes depend more on overall treatment quality than on absolute volume achieved: planning should focus on harmonious integration within the face rather than volumetric targets alone.
• Adverse events are frequent but generally mild and self-limiting: patients must be adequately informed prior to treatment.
• Differences across technologies do not yet allow definitive recommendations: product selection should be guided by the clinician's experience and patient characteristics, rather than by a hierarchy of evidence that remains insufficient at this stage.
Conclusion
Hyaluronic acid confirms its status as a safe and effective material for lip augmentation. The findings of this meta-analysis — the first to be based exclusively on RCTs — nonetheless call for a more critical and realistic appraisal of the treatment.
The key to success lies not in the product used, but in the correct indication for treatment, appropriate expectation management, and the clinician's ability to integrate the result within the patient's global facial aesthetic. As the body of evidence from controlled studies continues to grow, future analyses will enable increasingly robust recommendations and more personalised clinical guidance.
Author of this commentary:
Andrea De Santis - Member of the Focus Group Iniettabili del Volto - Agorà
ORIGINAL ARTICLE ABSTRACT
SUBJECT OF THIS COMMENTARY
Efficacy and Safety of Hyaluronic Acid Lip Fillers: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Aesthetic Surgery Journal, 2025, Vol 00(0) 1–9
DOI: 10.1093/asj/sjaf224
Efficacy and Safety of Hyaluronic Acid Lip Fillers: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Y. Edward Wen, MD; Lucas R. Perez Rivera, BS; Hailey P. Wyatt, MD; Wen-Yu Lee, MS; Cheongeun Oh, PhD; Carter J. Boyd, MD, MBA; Nolan S. Karp, MD
Despite the growing demand for hyaluronic acid (HA) lip fillers, there is a paucity of robust, quantitative data across high-powered studies. This systematic review and meta-analysis aims to assess the efficacy and safety of HA lip fillers as reported by randomized controlled trials (RCTs). A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses 2020 guidelines, utilizing PubMed, Embase, and Cochrane, and eligible studies included RCTs with human participants utilizing HA filler for lip augmentation. Meta-analysis evaluated rates of improvement in lip fullness, aesthetic appearance, patient satisfaction, and adverse events. A comprehensive review initially identified 2038 articles. Following screening by title and abstract, full-text review, and risk of bias assessment with the Cochrane risk-of-bias tool for randomized trials, 16 articles were included in the study. Meta-analysis demonstrated that 60% (95% CI, 44%-76%) had improvement in lip fullness, 82% (95% CI, 67%-92%) had improvement in aesthetic appearance, 68% (95% CI, 58%-78%) reported satisfaction, 50% (95% CI, 27%-73%) had adverse events, and 1.1% (95% CI, 1.9-4.0%) had serious adverse events requiring treatment, needing follow-up, or lasting beyond 30 days. The most common adverse events were swelling (78%), firmness (48%), bruising (34%), and tenderness (33%). Across studies with the highest level of evidence, HA filler efficacy and patient satisfaction was moderate to high. Severe adverse reactions were rare, but adverse events were common.
Keywords: hyaluronic acid, lip fillers, lip augmentation, systematic review, meta-analysis, randomized controlled trials, adverse events, patient satisfaction
FULL-LENGTH ORIGINAL ARTICLE
Comments