What Is Slugging? The Petroleum Jelly Trick, Explained
Sealing the face with a thin layer of petrolatum overnight so nothing evaporates. Named for how it looks.
On the label
Not a product, a habit. Any plain occlusive balm does it.
What it does not mean
It does not add hydration by itself, and it is not for oily or congested skin. It keeps in what the serum underneath brought.