Injectable Fillers and Collagen Stimulators for Facial Aesthetics: Products, Indications, Techniques, and Complications

BACKGROUND: Injectable dermal fillers are among the most commonly performed aesthetic procedures worldwide, reflecting a shift toward minimally invasive facial rejuvenation. Modern fillers address not only wrinkles but also structural support, volume loss, and skin quality. Available products, including hyaluronic acid (HA), calcium hydroxyapatite (CaHA), poly-L-lactic acid (PLLA), polycaprolactone (PCL), autologous fat, and polymethylmethacrylate (PMMA), vary in mechanism, rheology, longevity, and safety profile. OBJECTIVE: To review currently available facial injectable fillers, clinical indications, injection techniques, safety considerations, and emerging innovations. METHODS: A narrative review of published literature was conducted, examining filler-specific characteristics, facial aesthetic indications, multilayer injection strategies, and evidence-based complication prevention and management. RESULTS: HA fillers provide immediate volumization with reversibility and remain first-line for many indications. CaHA, PLLA, and PCL offer combined volumizing and biostimulatory effects through neocollagenesis, making them useful for structural support and longer-lasting correction. Autologous fat provides regenerative cellular potential, while PMMA offers permanent correction in selected patients. Anatomy-based, layered injection techniques improve aesthetic outcomes and reduce complications. Most adverse events are mild and transient; however, rare vascular occlusions require prompt recognition and intervention. New innovations focus on hybrid formulations and the regenerative potential of fillers. CONCLUSION: Injectable fillers are central to contemporary aesthetic dermatology, evolving toward anatomy-driven and regenerative treatment paradigms. Optimal outcomes depend on detailed anatomic knowledge, individualized product selection, technical precision, and proactive complication management.