Caffeine is most associated with coffee, tea, and cacao. In skincare, it helps with calming inflammation and is rich in antioxidants.

While caffeine is used to treat cellulite and and dark circles, further studies are needed to prove this. It has been believed to help with these skin conditions due to its ability to dilate blood vessels and increase blood flow.

This is the synthetic salt of gluconic acid, a form of PHA and mild exfoliant.

It is mainly used to stabilize oil and butter formulations from going bad. Sodium gluconate is a humectant, pH regulator, and chelating agent.

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.