Filler selection drives both clinical outcomes and practice economics. The market has fragmented into distinct families—hyaluronic acid (HA), biostimulators (PLLA and CaHA), dynamic/rheologic HA variants, and hybrid platforms—each with different crosslinking profiles, diffusion patterns, longevity windows, and per-unit costs. Owners must understand not just where each filler works best, but how their rheology, particle size, and degree of crosslinking affect patient satisfaction, touch-up frequency, and margin per syringe. This guide maps the major families and their clinical-economic trade-offs so you can stock the right portfolio for your patient mix and payer mix.