Exploratory Evaluation of a Hyper-Diluted Calcium Hydroxyapatite–Hyaluronic Acid Combination for Facial Rejuvenation: A Pilot Study

Facial aging results from intrinsic and extrinsic factors causing soft tissue volume loss, skin laxity, and wrinkles; minimally invasive fillers combining calcium hydroxyapatite (CaHA) and hyaluronic acid (HA) may mitigate these changes. This pilot study explored the feasibility, safety, and preliminary efficacy of a hyper-diluted 1:1 CaHA-HA combination in nine patients (30–65 years) with mild-to-moderate facial volume loss and laxity. Injections were delivered to affected areas using blunt-tip cannulas and fine needles. Clinical outcomes were measured with the Merz Aesthetic Scale (MAS), Wrinkle Severity Rating Scale (WSRS), and Global Aesthetic Improvement Scale (GAIS), while adverse events and patient satisfaction were recorded. MAS showed notable improvements in upper cheek fullness, lower cheek fullness, and jawline contour (+0.94, +0.94, and +0.89, respectively), and WSRS nasolabial fold severity decreased from 3.28 ± 0.18 to 2.50 ± 0.00 (p < 0.0001) with large effect sizes (Cohen’s d > 5.0). All patients rated themselves “very improved” on GAIS; no adverse events were reported, and satisfaction was high. These preliminary findings suggest that hyper-diluted CaHA–HA may be a safe and promising minimally invasive approach for facial rejuvenation, although confirmation in larger, controlled studies with longer follow-up is required.