What is slugging in skincare?

Slugging is the skincare habit of putting a thick occlusive layer on top of your nighttime routine so moisture does not evaporate as quickly. Petrolatum is the classic version, and the goal is to lock in what you already applied underneath.

It can help dry or irritated skin, especially in cold or windy conditions. It is less helpful if your skin is very acne-prone or if you already react badly to heavy products, because more occlusion is not always better.

The practical version is simple: moisturize first, then apply a thin layer of occlusive as the last step. If it feels like too much, it probably is.