Abstract
BACKGROUND: With the continuous increasing availability of new filler products, each hyaluronic acid filler brand has distinctive pharmacokinetics, which may be associated with different complications. Therefore, the long-term safety of new generations of fillers should be evaluated. OBJECTIVE: This prospective, multicenter, observational, postmarketing study ( ClinicalTrials.gov identifier: NCT04738019) aimed to investigate the incidence of delayed-onset nodules and adverse reactions after the injection of new hyaluronic acid fillers (YYS series) into the facial skin. METHODS: Subjects scheduled to receive an injection YYS series filler were followed up for 52 weeks. The authors aimed to determine the incidence of a self-reported delayed-onset nodule-a visible or palpable nodule or mass at the injection site that was detected beyond the 14th day following the injection-during the 1-year follow-up period. RESULTS: Among the 1,022 subjects who received an injection of the YYS series, the incidences of delayed-onset nodules were 0% for YYS 360, YYS 540, and YYS 720. A 0.21% incidence (1 delayed hypersensitivity reaction) of a delayed-onset adverse reaction was noted for YYS 720, although none were reported for YYS 360 and YYS 540. CONCLUSION: In this study, a notably low frequency of adverse reactions associated with the YYS series was observed.