Melanin skin pigment forms through the progressive oxidation of the amino acid tyrosine. The main steps in the process of melanogenesis were analyzed by Raper and Mason. The major oxidation steps, from tyrosine to dopaquinone, are catalyzed by tyrosinase. The degree of skin pigmentation can be regulated by controlling the melanogenesis reaction. Vitamin C can inhibit or slow down the activity of tyrosinase and suppress the production of melanin.
Topical application can help to prevent freckles and brown age spots, and improve skin tone.
Once applied to the skin's surface it cannot be rubbed off, washed off, or perspired off for three days. So, the protection is long-lived. Sun Damage Control Vitamin C amounts have been shown to be considerably lower in sun damaged skin than in normal skin. Skin is far less damaged, if Vitamin C is applied before sun exposure, and it recovers more quickly from sun damage after application. This information leads us to the assumption that a properly formulated Vitamin C product can prevent and repair sun damage, helping to reverse aging.