Sunday Riley C.E.O. 15% Vitamin C Brightening Serum Versus Authentic Ego Tidy Pores Water Jelly Lipid Peroxidation Serum With Stabilized Vitamin C

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.

Acetamidoethoxyethanol (long name!) is a recently developed synthetic humectant. The manufacturer claims this humectant can help keep skin moisturized for over 30 hours.

This ingredient helps bind the water molecules in the top layer of our skin using water and keratin. Keratin is a protein found in our skin that protects our skin from bacteria and infection.

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.