Cyclopentasiloxane, or D5, is a silicone used to improve texture of products and trap moisture.

D5 is considered lightweight and volatile. Volatile means it evaporates quickly after application. Once evaporated, D5 leaves a thin barrier that helps keep skin hydrated.

Disteardimonium Hectorite comes from the clay mineral named hectorite. It is used to add thickness to a product.

It can also help stabilize a product by helping to disperse other ingredients.

Isododecane is a fragrance, emollient, and solvent.

As an emollient, it helps your skin stay soft and hydrated. Emollients help trap moisture into your skin.

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.

This ingredient is a solvent. It helps dissolve active ingredients and alter the texture of products.

Propylene Carbonate is commonly used in makeup and with clay, such as montmorillonite or bentonite.

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.