Neutrogena Hydro Boost Hydrating Lotion SPF 25 Versus Dermalogica Matte Defense SPF 30

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.

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.

Octocrylene protects skin from sun damage. It absorbs UV-B with peak absorption of 304 nm. It is a common sunscreen ingredient and often paired with avobenzone, a UVA filter. This is because octocrylene stabilizes other sunscreen ingredients by protecting them from degradation when exposed to sunlight. Octocrylene is a photostable ingredient and loses about 10% of SPF in 95 minutes.

Octocrylene also acts as an emollient, meaning it helps skin retain moisture and softens skin. It is oil-soluble and hydrophobic, enhancing water-resistant properties in a product.

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, also known as silicon dioxide, is a naturally occurring mineral. It is used as a fine, spherical, and porous powder in cosmetics.

Though it has exfoliant properties, the function of silica varies depending on the product.

Sodium Ascorbyl Phosphate is a form of Vitamin C. It is the salt of ascorbic acid.

This ingredient is more gentle than ascorbic acid. It is also more stable when exposed to light and oxygen.

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.

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.