Kiehl's Since 1851 Vital Skin-Strengthening Hyaluronic Acid Super Serum, 1.7-oz.

Tocopherol, or Vitamin E, is an antioxidant that helps protect the skin from free radical damage. It also has moisturizing properties. It is beneficial for maintaining healthy skin.

A form of hyaluronic acid, it is used for its superior hydrating properties. It helps retain moisture in the skin and improve elasticity. It is beneficial for all skin types, especially dry and dehydrated skin.

Glycerin is a humectant that attracts moisture to the skin. It is widely used in skincare for its hydrating properties. It helps improve skin barrier function and smoothness.

Also known as witch hazel water, it is used for its soothing and anti-inflammatory properties. It can help reduce skin irritation and redness. It is beneficial for oily and acne-prone skin.

This extract is known for its antioxidant and anti-inflammatory properties. It helps protect the skin from environmental stressors. It is beneficial for soothing and revitalizing the skin.

A derivative of salicylic acid, it is used for its exfoliating properties. It helps unclog pores and improve skin texture. It is beneficial for acne-prone skin.

Ginseng extract is known for its antioxidant and anti-aging properties. It helps improve skin elasticity and reduce the appearance of wrinkles. It is beneficial for revitalizing and rejuvenating the skin.

Also known as holy basil, this extract has antioxidant and anti-inflammatory properties. It helps protect the skin from environmental stressors. It is beneficial for soothing and revitalizing the skin.

Adenosine is known for its anti-aging and skin-soothing properties. It helps improve the appearance of fine lines and wrinkles. It is beneficial for promoting smoother and more youthful-looking skin.

Water is a common solvent used in cosmetic formulations. It helps dissolve other ingredients and provides a base for the serum. It does not have any direct benefits or risks.

Propanediol is a glycol used as a solvent and skin-conditioning agent. It enhances the absorption of other ingredients. It is generally considered safe and non-irritating.

This ingredient is used as a thickening agent in cosmetics. It helps stabilize emulsions and improve product texture. It is generally considered safe for use in skincare.

Caprylyl glycol is used as a skin-conditioning agent and preservative. It helps improve the texture and feel of the product. It is generally considered safe for use in cosmetics.

Xanthan gum is a natural thickening agent used to stabilize emulsions. It helps improve the texture and consistency of the product. It is generally considered safe and non-irritating.

This ingredient is used as an emulsifier and surfactant. It helps blend oil and water-based ingredients. It is generally considered safe for use in cosmetics.

This ingredient is used as an emulsifier and surfactant. It helps blend oil and water-based ingredients in formulations. It is generally considered safe for use in cosmetics.

Orange peel oil is used for its fragrance and potential antioxidant properties. It can enhance the sensory experience of the product. However, it may cause irritation in sensitive skin.

Sodium hydroxide is used to adjust the pH of cosmetic formulations. It is used in very small amounts to ensure product stability. It is generally considered safe when used appropriately.

This ingredient is used as a fragrance component in cosmetics. It provides a floral scent to enhance the sensory experience. It is generally considered safe for use in cosmetics.

Citric acid is used to adjust the pH of cosmetic formulations. It also has mild exfoliating properties. It is generally considered safe for use in cosmetics.

Geranium flower oil is used for its fragrance and potential skin benefits. It may have balancing and soothing properties for the skin. However, it can cause irritation in sensitive individuals.

Lavender oil is used for its fragrance and potential calming properties. It may help soothe the skin and provide a relaxing scent. However, it can cause irritation in sensitive individuals.

Lemongrass oil is used for its fragrance and potential antimicrobial properties. It provides a fresh, citrus scent to cosmetic products. However, it can cause irritation in sensitive individuals.

Rosemary oil is used for its fragrance and potential antioxidant properties. It may help invigorate the skin and provide a fresh scent. However, it can cause irritation in sensitive individuals.

Occlusive silicone film-former — flagged under clean-beauty doctrine.

Phenoxyethanol is a preservative used to prevent microbial growth. It can cause irritation and allergic reactions in some individuals. It is considered a safer alternative to parabens.

Processed additive flagged under Scout's ingredient doctrine.

Limonene is a fragrance component that can cause skin irritation. It is used for its citrus scent in cosmetics. It may oxidize and become more irritating over time.

Eugenol is a fragrance component that can cause skin irritation. It is used for its spicy, clove-like scent in cosmetics. It may cause allergic reactions in sensitive individuals.

Synthetic preservative that can form benzene in the presence of vitamin C.

Citral is a fragrance component that can cause skin irritation. It is used for its lemon scent in cosmetics. It may cause allergic reactions in sensitive individuals.

Synthetic preservative — flagged in daily-use products.

Citronellol is a fragrance component that can cause skin irritation. It is used for its floral scent in cosmetics. It may cause allergic reactions in sensitive individuals.

Linalool is a fragrance component that can cause skin irritation. It is used for its floral scent in cosmetics. It may cause allergic reactions in sensitive individuals.

Geraniol is a fragrance component that can cause skin irritation. It is used for its rose-like scent in cosmetics. It may cause allergic reactions in sensitive individuals.

Denatured alcohol is used as a solvent and astringent. It can be drying and irritating to the skin, especially in high concentrations. It may disrupt the skin's natural barrier.