Garnier Light Complete Vitamin C Serum Versus Estée Lauder Perfectionist Pro Serum Rapid Brightening Treatment with Ferment² + Vitamin C

Bis-Peg-18 Methyl Ether Dimethyl Silane belongs to the siloxanes and silicones classes. It is synthetically created and has a waxy composition.

This ingredient is a humectant and emollient, meaning it helps hydrate the skin. Humectants draw moisture to your skin, while emollients prevent moisture from escaping.

Isononyl Isononanoate is a synthetic skin-conditioner and texture enhancer. It is created from nonanoic acid, a fatty acid found in cocoa and lavender oil.

As an emollient, Isononyl Isononanoate helps keep your skin soft and smooth. This is because emollients create a barrier on the skin to trap moisture in.

BHT is a synthetic antioxidant and preservative.

As an antioxidant, it helps your body fight off free-radicals. Free-radicals are molecules that may damage your skin cells.

Parfum is a catch-all term for an ingredient or more that is used to give a scent to products.

Also called "fragrance", this ingredient can be a blend of hundreds of chemicals or plant oils. This means every product with "fragrance" or "parfum" in the ingredients list is a different mixture.

Salicylic Acid (also known as beta hydroxy acid or BHA) is one of the most well-known ingredients for treating skin that struggles with blackheads and acne. It helps to exfoliate both the skin's surface and pores, and also acts as an anti-inflammatory agent.

This multitasking property makes it a great ingredient for cleaning out pores, controlling oil production, and reducing inflammation.

Sodium Citrate is the sodium salts of citric acid. In skincare, it is used to alter pH levels and acts as a preservative.

Its main functions are to maintain the pH of a product and neutralize metal ions.

Sodium Hyaluronate is hyaluronic acid's salt form. It is commonly derived from the sodium salt of hyaluronic acid.

Like hyaluronic acid, it is great at holding water and acts as a humectant. This makes it a great skin hydrating ingredient.

Phenoxyethanol is a preservative that has germicide, antimicrobial, and aromatic properties. Studies show that phenoxyethanol can prevent microbial growth. By itself, it has a scent that is similar to that of a rose.

It's often used in formulations along with Caprylyl Glycol to preserve the shelf life of products.

Tocopheryl Acetate is AKA Vitamin E. It is an antioxidant and protects your skin from free radicals. Free radicals damage the skin by breaking down collagen.

One study found using Tocopheryl Acetate with Vitamin C decreased the number of sunburned cells.

Disodium EDTA plays a role in making products more stable by aiding other preservatives.

It is a chelating agent, meaning it neutralizes metal ions that may be found in a product.

Citric Acid is an AHA derived from citrus fruits (think oranges, lemons, and limes!).

As an AHA, Citric Acid removes the top layer of skin cells from the newer layer of skin underneath. This helps skin to remove dark spots and even out skin tone.

Xanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.

On the technical side of things, xanthan gum is a polysaccharide - a combination consisting of multiple sugar molecules bonded together.