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.

Ceramide NP is a type of ceramide.

Ceramides are intercellular lipids naturally found in our skin that bonds dead skin cells together to create a barrier. They are known for their ability to hold water and thus are a great ingredient for dry skin.

Glutamic Acid is an amino acid that is found in all living organisms. Our bodies use this to help nerve cells in the brain communicate with other cells.

In cosmetics, glutamic acid is a famous humectant. It draws water from the air to your skin, keeping your skin hydrated (like hyaluronic acid).

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.

This ingredient is an amino acid that helps build proteins and moisturizes skin. It is already present in our skin as our bodies produce them naturally.

Glycine already plays a role in helping keep our skin moisturized as amino acids transport moisture throughout our skin.

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.

Lysine is an essential amino acid. Your body is unable to produce it naturally and we mainly get lysine from food sources.

Our bodies use lysine for growth and tissue repair. The skin uses amino acids as a precursor for building protein, and therefore keratins, collagen and elastin.

Phytosterols come from plants, nuts, and whole grains. These compounds have skin soothing and moisturizing properties.

Fun fact: They are similar to cholesterol and can help lower cholesterol levels.

Proline is an amino-acid. It helps moisturize the skin and plays an important role in creating proteins.

Our skin uses proline as one of the building blocks for producing collagen.

Serine is an amino acid naturally found in our body. Our bodies use amino acids to create protein.

Amino-acids help give keep our skin hydrated. They play an important role in the skin barrier, which keeps the skin plump and firm.

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.

Threonine is an amino-acid. It helps hydrate the skin and has antioxidant benefits.

Our skin uses threonine for creating collagen and elastin. Humans are not able to create threonine and must get it through eating foods such as fish, lentils, poultry, sesame seeds, and more.

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.