First things first: Biostimulatory fillers aren’t actually fillers, at least in the traditional sense, according to Julie Russak of Russak Dermatology Clinic in New York City. Unlike hyaluronic acid fillers, these injectables aren’t made to plump up skin or mask volume loss—instead, they target deeper signs of aging like declining bone mass, skin sagging, and less elasticity.
As the name suggests, these fillers work to encourage cell regeneration. “When they’re injected close to the bone, they actually stimulate regeneration in those tissues, and when they’re injected close to fibroblasts, the cells in our body that produce collagen and elastin, they stimulate regeneration there,” says Russak. The two types in the U.S. right now are Sculptra, which increases energy production in cells, and Radiesse, which is essentially calcium that improves bone structure.