Free radical scavenging properties of mannitol and its role as a constituent of hyaluronic acid fillers: a literature review.

Mannitol has both hydrating and antioxidant properties that make it an ideal excipient for use with hyaluronic acid (HA) fillers. This review examines the role of reactive oxygen species in the ageing process and their effects on both endogenous HA and HA products developed for aesthetic use. Evidence is presented to show that the free radical scavenging properties of mannitol provide it with a two-fold mechanism of action when combined with HA fillers: reducing the inflammation and swelling associated with the injection procedure itself, and preventing the degradation of the injected HA by free radicals. Mannitol also has a long- and well-established safety profile in both the food and pharmaceutical industry. Having established the rationale for using mannitol in combination with an HA filler, the products using this strategy are then reviewed. The addition of mannitol to HA fillers is a viable and safe option for improving both short- and long-term HA aesthetic effects.