Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:

Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.

Camellia Sinensis Leaf Water is a tonic and helps with masking.

Tonics are used to remove soap residues. They also help moisturize the skin.

This ingredient is an emollient, solvent, and texture enhancer. It is considered a skin-softener by helping the skin prevent moisture loss.

It helps thicken a product's formula and makes it easier to spread by dissolving clumping compounds.

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.

Ethylhexylglycerin (we can't pronounce this either) is commonly used as a preservative and skin softener. It is derived from glyceryl.

You might see Ethylhexylglycerin often paired with other preservatives such as phenoxyethanol. Ethylhexylglycerin has been found to increase the effectiveness of these other preservatives.

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.

Hydrogenated Polydecene is an emollient. It creates a non-occlusive film on the skin that offers extra protection for your skin barrier.

The texture of Hydrogenated Polydecene ranges from light and silky to rich.

Hydrolyzed Hyaluronic Acid is a form of hyaluronic acid. It is created by the hydrolysis of hyaluronic acid with a high molecular weight. Once created, Hydrolyzed Hyaluronic Acid has a low molecular weight.

Low molecular weight HA has been shown to hydrate and increase elasticity of the skin. Increasing elasticity is also associated with reduction of wrinkle depth.

Hydroxyacetophenone is antioxidant with skin conditioning and soothing properties. It also boosts the efficiency of preservatives.

This ingredient is not irritating or sensitizing.

Polyquaternium-51 is a polymer salt. It helps hydrate the skin by creating a film on top. This film traps moisture in, keeping your skin soft and hydrated.

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.

Sodium Stearoyl Glutamate is an emulsifier and helps condition the skin. It is amino acid-based.

In higher amounts, it may act as a cleansing agent.

Vinyldimethicone is a type of silicone.

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.