Summary: 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.
Chang et al. (Thu,) studied this question.