How to Slug and Use Sleeping Packs the Right Way

Slugging means applying an occlusive layer (often petrolatum-based) as the final nighttime step to help reduce overnight water loss. Korean sleeping packs serve a similar sealing purpose with lighter, leave-on overnight textures.

How Occlusion Works

An occlusive layer sits on the skin's surface and helps slow transepidermal water loss, so the hydration underneath stays put longer. This is why slugging is often suggested for very dry skin or compromised barriers, typically over a moisturizer rather than on bare skin.

Doing It Safely

Apply your usual hydrating layers and moisturizer first, then a thin occlusive layer or sleeping pack on top. Because occlusion traps whatever is underneath, avoid layering strong actives (like retinoids or acids) directly beneath a heavy occlusive, which can intensify their effect and cause irritation. Use a clean pillowcase, since occlusives can transfer.

Who Should Be Cautious

Slugging suits dry and dehydrated skin best. Those prone to congestion or breakouts may prefer a lighter sleeping pack to a heavy occlusive, or may slug only on the driest areas. Patch-test new sleeping packs, and if your skin feels congested afterward, scale back the frequency.

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Sources

• Petroleum jelly - Wikipedia ↗

✍️ Written & reviewed by the KoreaPlus Editorial team — dermatologist-informed, cosmetic-science researched & source-cited. Last reviewed 2026-06-21.

General educational information using cosmetic structure-function wording — not medical advice. Always patch-test new actives. © KoreaPlus.