Vitamin C is an effective antioxidant that brightens the skin tone and reduces the appearance of signs of aging. The format of this formula is a suspension of very fine L-Ascorbic Acid powder and, as such, provides the most direct exposure of extremely high concentrations of Vitamin C topically. Directions Apply a small amount to face in the AM or the PM (PM preferred). A tingling sensation can be expected after application. If the sensation is too strong to tolerate, the formula can be mixed on each application with other creams or serums of your preference.