The Slugging Method Is Moving From Face to Ends of Hair

Slugging — coating skin in an occlusive layer like petroleum jelly overnight to lock in moisture — became a widely adopted skincare technique a few years ago, and the same logic is now being applied specifically to hair ends, the driest and most damage-prone part of most heads of hair.

The hair version typically uses a lighter oil or specifically formulated overnight treatment rather than pure petroleum jelly, applied only to the ends to avoid weighing down roots or leaving an unwanted residue closer to the scalp. Left overnight under a protective wrap or bonnet, the occlusive layer is meant to reduce overnight moisture loss the same way it does for skin.

Stylists working with damaged or color-treated ends report the technique produces a noticeable softness improvement within a few applications, consistent with how occlusives are understood to work — not adding moisture directly, but preventing what moisture is already present from evaporating.

It's a fairly direct borrow from skincare's playbook, but one where the underlying mechanism transfers cleanly enough that the crossover holds up better than most beauty-industry trend borrowing tends to.