EltaMD, Inc UV Replenish SPF 44 Versus Dermalogica Invisible Physical Defense SPF 30

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.

Polyhydroxystearic Acid is a soft wax made from castor oil.

It is is a texture thickener, emulsifier, and film-former. Emulsifiers prevent ingredients from separating, such as oils and waters.

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.

Chances are, you eat sodium chloride every day. Sodium Chloride is also known as table salt.

This ingredient has many purposes in skincare: thickener, emulsifier, and exfoliator.

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.

Tocopheryl Acetate is AKA Vitamin E. It is an antioxidant and protects your skin from free radicals. Free radicals damage the skin by breaking down collagen.

One study found using Tocopheryl Acetate with Vitamin C decreased the number of sunburned cells.

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.

Zinc Oxide is a mineral broad-spectrum UV filter; it is the broadest UVA and UVB reflector approved by the FDA. While it is most commonly man-made for cosmetics, it can naturally occur in zincite, a rare mineral.

Today, traditional and nano-sized zinc oxide can be found in beauty products. Nano-sized zinc oxide can enhance a product's UV protection. While it is not believed to have a negative effect on skin, nano-zinc oxide may be harmful to coral reefs - though the verdict is not entirely out on this one.