Glycerin is already naturally found in your skin. It helps moisturize and protect your skin.

A study from 2016 found glycerin to be more effective as a humectant than AHAs and hyaluronic acid.

Hexylene Glycol is a surfactant. Glycols are a class of alcohols. Hexylene Glycol is a surfactant and emulsifier.

As a surfactant, Hexylene Glycol helps gather dirt and oil on your skin to be washed away.

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.

Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin. 

It’s often used to:

Tetrasodium Glutamate Diacetate is a chelating agent. Chelating agents help prevent metal ions from binding to other ingredients. This helps prevent unwanted effects and reactions from a product. These metal ions may come from water and are found in miniscule amounts.

Tetrasodium Glutamate Diacetate can also help other preservatives be more effective.

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.