Abstract: Compositions comprising monodisperse phytoglycogen nanoparticles and a further moisturizing polysaccharide are disclosed as exhibiting a synergistically enhanced ability to moisturize the skin. Preferably, the phytoglycogen is isolated from plant matter such as sweet corn kernels. The moisturizing polysaccharide may be a glycosaminoglycan, a chitosan, an alginate, or a beta glucan. In preferred embodiments, the polysaccharide is hyaluronic acid. The compositions may optionally further comprise various carriers, fillers, and active agents.