This all-in-one serum is used right after cleansing, morning and evening. On dry skin, apply 2 to 3 pumps to the face and neck, gently massaging until fully absorbed. You can use it alone as a single treatment (toner + serum + light cream) or complement it with a moisturizer if your skin is dry. Don’t forget sunscreen during the day to boost the brightening effect of glutathione.