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.

Caffeine is most associated with coffee, tea, and cacao. In skincare, it helps with calming inflammation and is rich in antioxidants.

While caffeine is used to treat cellulite and and dark circles, further studies are needed to prove this. It has been believed to help with these skin conditions due to its ability to dilate blood vessels and increase blood flow.

Carbomer is a polymer of acrylic acid. Its main role is to create a gel consistency.

A high amount of carbomer can cause pilling or balling up of products. Don't worry, most products contain 1% or less of carbomer.

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.

We don't have a description for Glyceryl Polymethacrylate yet.

Palmitoyl Hexapeptide-12 is a synthetic peptide made with glycine, histidine, lysine, and palmitic acid.

The sequence of this peptide matches that of elastin, a key protein that plays a role in how firm our skin is.

PEG-8 is a synthetic polymer used as a humectant and solvent.

This ingredient is able to help dissolve active ingredients, including water. This gives it humectant properties.

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.

Sodium Citrate is the sodium salts of citric acid. In skincare, it is used to alter pH levels and acts as a preservative.

Its main functions are to maintain the pH of a product and neutralize metal ions.

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 Hydroxide is also known as lye or caustic soda. It is used to adjust the pH of products; many ingredients require a specific pH to be effective.

In small amounts, sodium hydroxide is considered safe to use. However, large amounts may cause chemical burns due to its high alkaline.

Sucrose is a natural sugar found in fruits, vegetables, and nuts. It is the main constituent of white sugar.

In skincare, sucrose is a humectant and can be a mild exfoliant.

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.