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.

Centella Asiatica Extract (Centella) is derived from an herb native to Southeast Asia. It is famous for its anti-inflammatory and soothing properties.

Centella is rich in antioxidants and amino acids, such as Madecassic Acid and Asiaticoside.

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.

This ingredient is created by distilling parts of the tea tree plant. The bark and leaves of the tea tree plant are rich in Terpinen, an antioxidant, antibacterial, and anti-inflammatory ingredient.

Tea tree may cause sensitivity and irritation for some people due to its linalool and limonene content.

Panthenol is a common ingredient that helps hydrate and soothe the skin. It is found naturally in our skin and hair.

There are two forms of panthenol: D and L.

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.