What is the difference between a serum and a face oil?

Serums are water-based products that have a smaller molecule size, so they can penetrate deeply into the skin. Serums hydrate and provide some of the most potent botanicals that work on the deeper layers of the skin. Face oils tend to have a larger molecule size than serums and work on the upper layers of the skin. Oils are extremely moisturizing and work to reinforce the skin barrier. We recommend using a serum and an oil daily. Serums should be applied first, allowed to completely absorb, and then oil should be applied next.