Fenty Beauty Soft’Lit Naturally Luminous Longwear Foundation Versus Maybelline Super Stay Lumi-Matte Foundation

Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.

Topically, glycerin does several things at once:

Magnesium Sulfate is a salt. More specifically, it is an epsom salt, or the bath salt used to help relieve muscle aches.

Despite having ‘sulfate’ in the name, it isn’t a surfactant or cleansing agent like sodium lauryl sulfate. Unlike those sulfates, magnesium sulfate doesn’t have the same cleansing or foaming properties (it's simply a type of salt).

Peg-10 Dimethicone is silicone with conditioner and emulsifier properties. It mostly acts as an emollient in skincare and and humectant in haircare.

According to the manufacturer, acidic formulations decrease the stability of this ingredient. It works best in neutral or near neutral formulations.

Synthetic Fluorphlogopite is the synthethic version of mica. It consists of fluorine, aluminum and silicate.

Synthetic Fluorphlogopite is used to add volume to products.

This silicone is an emollient. Emollients create a thin film on the skin to prevent moisture from escaping.

It is not soluble in water and helps increase water-resistance in 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.