Preliminary Investigation and Safety Profile of a Novel Hybrid Filler (Hyaluronic Acid–Calcium Hydroxylapatite) in Asian Facial Rejuvenation

Injectable fillers, such as hyaluronic acid (HA)-based fillers and calcium hydroxylapatite (CaHA) collagen stimulators, have been used to replenish lost volume by physically filling gaps or stimulating collagen synthesis. A commercially available hybrid filler combining HA and CaHA in a new gel-form collagen stimulator has yet to be extensively studied in an Asian population. This was a case series of patients attending 2 centers in Hong Kong between August 2023 and February 2024 to document the safety of HA-CaHA in Asian patients. Outcomes included patients' overall satisfaction with the treatment experience, based on the Global Aesthetic Improvement Scale assessment and treatment-emergent adverse events reported after treatment at the 3- and 6-month follow-ups. Twenty-five Chinese patients (22 female; age range [median]: 25-63 [37] y) received 2-3 syringes of HA-CaHA with a mean total volume of 2.8 mL (range: 2.5-3.75 mL). Immediately after treatment and at the 1- and 3-month follow-ups, 60% (15 of 25) of patients reported "very much improved," 32% (8 of 25) reported "much improved," 8% (2 of 25) reported "improved," and 0% reported "unchanged" or "worse" throughout the 6 months. Treatment-emergent adverse events immediately after treatment included bruising (n = 3, 12%), edema (n = 8, 32%), erythema (n = 1, 4%), tenderness (n = 3, 12%), and skin induration (n = 4, 16%). A hybrid filler combining HA and CaHA represents a promising advance in facial rejuvenation, offering immediate volumizing effects, longer-lasting results, and few adverse events.