excess melanin production in skin causes pigmentation. factors that can lead to melanin production are stress, pollutants, allergens, irritants and uv light ( sun ) exposure. oxylife proclear pure oxygen facial kit has actives that inhibit melanin production by tyrosinase inhibition, an enzyme necessary for melanin synthesis and the anti-oxidants that act upon free radicals to reduce the inflammatory response and also reduces melanocyte stimulation thereby reducing pigmentation