Clearstem Skincare Youaresunshine Sheer Broad-Spectrum SPF 50+ Versus Prequel Sun Barrier Mineral Sunscreen Broad Spectrum SPF 50 PA++++

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.

Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin. 

It’s often used to:

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.

Sorbitan Olivate is created from the fatty acids in olive oil and sorbitol.

This ingredient is an oil in water emulsifier. It helps stabilize a product by preventing oils and waters from separating. Sorbitan Olivate also helps hydrate the skin.

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.

Triethoxycaprylylsilane is a silicone used to bind and stabilize ingredients.

As an emulsifier, it helps prevent ingredients from separating. This can help elongate the shelf life of products.

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.

This ingredient is a combination of red, black, and yellow iron oxide pigments. This combination of colors is usually found in foundation, because it results in a "skin" color.