Featuring a "quad focus" approach to combat visible aging, this global serum acts as skin's first line of protection to help combat visible aging. Defend: Works to defend skin from environmental aggressors. Detox: Promotes natural cell removal, detoxing the skin of dead surface cells. Rebuild: Fortifies the skin's protective barrier to help inhibit future damage from occurring. Repair: Works around the clock to help promote skin's natural repair process and natural collagen production.