Obagi Professional-C Serum 20% 1oz, 30ml Grant your skin the defense it needs to stay healthy and fit with Obagi Professional-C Serum 20%. It's designed to visibly reduce the signs of aging, protect your skin from future damage from free radicals, and support healthy skin function. The smooth serum also boosts collagen, brightens skin tone, and restores needed moisture and hydration to improve the skin's tone and texture. This product is great for those with aging and sun-damaged skin. It also works well for people who have hyperpigmentation.CAUTIONS : Hydroquinone (HQ) and Tretinoin / Retinol products should not be used by pregnant women, women who intend to become pregnant in the near future, or women who are lactating/breast feeding. Test for skin sensitivity before using by applying a small amount to an unbroken patch of skin and check within 24 hours. Minor redness is not a contraindication, but where there is itching or vesicle formation or excessive inflammatory response, product should be discontinued and physician consulted. Close supervision is recommended. Sunscreen use is an essential aspect of HQ therapy because even minimal sunlight exposure sustains melanocytic activity. Avoid contact with eyes, nose, mouth, or lips. In case of accidental contact, rinse eyes, nose, mouth, or lips with water and contact physician.