The Balance of Beauty: Pooled Analysis of Adverse Events With a Cohesive Polydensified Matrix-Hyaluronic Acid Filler in Nasolabial Fold Treatments

Background Hyaluronic acid (HA) fillers are among the most widely used aesthetic treatments, valued for their safety, biocompatibility, and reversibility. Product-specific adverse events (AEs) are important to understand, especially delayed AEs. Objectives To evaluate the incidence, severity, and risk factors of AEs following nasolabial fold (NLF) treatment with CPM-B (cohesive polydensified matrix hyaluronic acid filler with 22.5 mg/ml HA; Belotero Balance®; Anteis S.A., Switzerland) across 5 internal clinical studies. Methods Pooled data included treatments to 526 NLFs in 412 patients. Adverse events were categorized into 12 subtypes and rated as mild, moderate, or severe. Multivariable logistic regression was used to evaluate the independent association of patient (age, sex) and procedure-related factors (injection volume, NLF laterality) with AE risk (≥1 vs 0). Results Adverse events were observed in 41% of treated NLFs; the majority (97%) were mild, with no severe AEs documented. The most common AEs included swelling (23%), erythema (20%), and bruising/ecchymosis (17%). Adverse event risk significantly increased with injection volume; every additional 100 µl raised the odds of an AE by 2.38 (P = .00537). Patient age, sex, and NLF laterality were not significantly associated with AE risk. Conclusions This study supports the overall safety and tolerability of CPM-B, with most AEs being mild and transient; only 3.8% were moderate, and none were severe. When controlling for study, volume was the only significant predictor of AE risk, highlighting the need for physicians to minimize excessive volumes where possible. Future studies should explore AE predictors in more diverse populations and investigate additional risk factors to optimize safety and outcomes.