Cholesterol is a class of organic molecules called lipids. It helps hydrate your skin and is essential to having a healthy skin barrier.

Our skin naturally contains cholesterol in the outermost layer. Besides cholesterol, it also contains ceramides and fatty acids. Cholesterol makes up about 1/4 of your skin's outer layer and barrier. Your skin barrier is responsible for keeping allergens and microbes out. Having a healthy skin barrier is also responsible for keeping your skin firm and plump.

Dimethicone is a type of synthetic silicone created from natural materials such as quartz.

What it does:

This ingredient is a silicone used to improve the texture of products and absorb oil. It does not get absorbed into the skin.

Like other silicones, Dimethicone/Vinyl Dimethicone Crosspolymer helps condition the skin by creating a barrier. In this sense, it can act as an emollient and trap moisture in.

Hydrogenated Lecithin is created from the hydrogenation of lecithin (a group of phospholipids). Hydrogenation is a chemical reaction between hydrogen and another element.

This ingredient is an emollient and emulsifier. As an emollient, it helps soften skin by trapping moisture within. As an emulsifier, it prevents oil and water ingredients from separating.

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.

Polysorbate 80 is a surfactant and emulsifier. It is used to keep ingredients together, and prevent oils and waters from separating.

It is made from polyethoxylated sorbitan and oleic acid. This ingredient can be found in cosmetics, foods, and medicine. It is water-soluble.

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.

Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.

So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.