Paula's Choice Resist Skin Restoring Moisturizer With SPF 50 Versus Kiehl's Ultra Facial Cream SPF 30

Dimethicone is a type of synthetic silicone created from natural materials such as quartz.

What it does:

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.

Ethylhexyl Salicylate is an organic compound used to block UV rays. It primarily absorbs UVB rays but offers a small amount of UVA protection as well.

Commonly found in sunscreens, Ethylhexyl Salicylate is created from salicylic acid and 2-ethylhexanol. You might know salicylic acid as the effective acne fighter ingredient and BHA.

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.

Glyceryl Stearate is a mix of glycerin and stearic acid.

It is used to stabilize the mixing of water and oil ingredients. By preventing these ingredients from separating, it can help elongate shelf life. It can also help thicken the product's texture.

Homosalate is a chemical sunscreen filter that provides protection in the UV-B range (280nm - 320 nm), with a peak protection at 306 nm. It is internationally approved for use in sunscreens.

Homosalate is not photo-stable, meaning it's strength as a UV filter degrades over time with exposure to the sun. Because of this, it's often used in combination with other chemical sunscreen filters as avobenzone (which protects from the UV-A range). Homosalate also helps act as a solvent for harder-to-dissolve UV filters.

Peg-100 Stearate is an emollient and emulsifier. As an emollient, it helps keep skin soft by trapping moisture in. On the other hand, emulsifiers help prevent oil and water from separating in a product.

PEGS are a hydrophilic polyether compound . There are 100 ethylene oxide monomers in Peg-100 Stearate. Peg-100 Stearate is polyethylene glycol ester of stearic acid.

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.

Silica is a mineral naturally found in our skin. It helps to thicken and smooth the texture of a product. It also acts as an agent for other ingredients by increasing the absorption of other ingredients into the skin.

Silica is often used for absorption and can help reduce shine when products are applied. Silica occurs in naturally in materials like clay and sandstone, and it can also be produced synthetically.

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.

Tocopherol (also known as Vitamin E) is a common antioxidant used to help protect the skin from free-radicals and strengthen the skin barrier. It's also fat soluble - this means our skin is great at absorbing it.

Vitamin E also helps keep your natural skin lipids healthy. Your lipid skin barrier naturally consists of lipids, ceramides, and fatty acids. Vitamin E offers extra protection for your skin’s lipid barrier, keeping your skin healthy and nourished.

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.

Xanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.

On the technical side of things, xanthan gum is a polysaccharide - a combination consisting of multiple sugar molecules bonded together.