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.

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.

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.

Hyaluronic acid is naturally found in healthy skin. It is a humectant, meaning it draws moisture to your skin.

This ingredient helps hydrate, soothe, and protect the skin.

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.

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.

This ingredient is created by putting sodium hyaluronate through hydrolysis.

You might know this as 'mini' or 'ultra low-molecular weight' hyaluronic acid. The small molecule size means it is able to travel deeper in the skin.

This form of hyaluronic acid is produced through fermentation.

According to a manufacturer, it has a positive charge by ionic binding to help moisturize and give hair a smooth feel. This is why you'll find this ingredient in shampoos and body washes.

Methylpropanediol is a synthetic solvent and humectant.

As a solvent, it helps dissolve other ingredients, helping to evenly distribute ingredients throughout the product. This ingredient has also been shown to have antimicrobial properties which makes it a preservative booster.

Potassium hyaluronate (PH) is a salt form of hyaluronic acid and has similar skin hydrating benefits.

Similar to hyaluronic acid, PH is able to draw and hold moisture to your skin. This helps keep skin soft and hydrated.

Sodium Acetylated Hyaluronate is a type of Hyaluronic Acid.

Hyaluronic Acids help moisturize, soothe, and protect the skin.

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 Hyaluronate Crosspolymer is a type of hyaluronic acid. In fact, it is modified version of hyaluronic acid.

The structure of Sodium Hyaluronate Crosspolymer allows it to stay in the skin's top layer for a longer period of time. This allows for even more hydration and humectant action than hyaluronic acid.

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.