Kiehl's Since 1851 Dermatologist Solutions Powerful-Strength Vitamin C Serum, 1.7 fl. oz.

Propylene Glycol is a common solvent and humectant used in skincare products. It helps to retain moisture in the skin but is a synthetic compound. While generally recognized as safe, it may cause irritation in sensitive individuals.

Adenosine is a beneficial ingredient known for its anti-aging properties. It helps to smooth the skin and reduce the appearance of wrinkles. It is well-tolerated and enhances skin's appearance by promoting collagen production.

Ascorbic Acid, also known as Vitamin C, is a potent antioxidant that protects the skin from free radical damage. It brightens the skin and improves overall skin tone. It is a high-quality active ingredient essential for collagen synthesis.

Ascorbyl Glucoside is a stable form of Vitamin C that provides antioxidant benefits. It helps to brighten the skin and reduce signs of aging. It is less irritating than pure Vitamin C, making it suitable for sensitive skin.

Boron Nitride is used in cosmetics for its soft-focus effect, which helps to blur imperfections. It is an inert compound with no significant health concerns. It enhances the texture and application of skincare products.

Cetyl PEG/PPG-10/1 Dimethicone is a silicone-based compound used for its emollient and conditioning properties. It provides a smooth application and enhances the feel of the product. It is generally considered safe but is a synthetic ingredient.

Citral is a fragrance component that can cause allergic reactions in some individuals. It is a natural compound found in citrus oils but can be irritating to the skin. Its primary use is for fragrance, which may not be necessary in skincare products.

Citrus Aurantium, also known as bitter orange, is used for its fragrance and potential antioxidant properties. It is a natural ingredient but can cause photosensitivity. Its primary role is to enhance the scent of the product.