SKIN TEST--A completed skin irritation test can help predict if you will have a specific reaction to a new product. Once your skin adapts, apply 3-6 drops of our serum to the dry and clean face, and then follow up with a moisturizer to enhance the moisturizing effect. If you have any questions about our product, please feel free to contact us directly. We are here to help you!. ANTI-OXIDATION-- With antioxidant effects, it helps defend the skin against free radicals, contributing to premature aging and skin damage. RADIANT&GLOWING --Our glutathione serum is a simple and effective solution for glowing, radiant skin, suitable for most skin types, including dry, oily, normal, combination, sensitive, etc. Perfect for aging skin and uneven skin tone. EVEN SKIN TONE-- Our vitamin C glutathione skin serum effectively addresses skin problems such as dark spots, uneven skin tone, wrinkles, and fine lines, promoting a more even skin tone and enhancing skin elasticity and firmness for a youthful appearance. POWERFUL INGREDIENTS--Our glutathione serum is rich in glutathione, vitamin C, niacinamide, and hyaluronic acid; this helps to hydrate and moisturize skin, reduce dark spots, wrinkles, fine lines, and even skin tone for a smoother and more radiant complexion.