The two MATER Beauty face serums are designed to work synergistically together as an entire post-cleansing routine, no other product needed (other than sunscreen on top, of course!).
They're loaded with actives, and can be used both morning and night. To pack the most goodness into them, one is water based and the other oil based. It’s how and why they work best together - healthy skin needs both water and oil to look its best.