In the cold, January weather, the reality is that I need a little extra hydration oomph before applying my go-to nightcream. My favorite right now is this serum from ZO Skin Health, which I apply after double-cleansing and splashing cold water on my face to close my pores. It rejuvenates my skin and protects it from flaking off post-retinol application.

Buy ZO Skin Health Ossential Growth Factor Serum Plus, $148.