An occlusive moisturiser, Vaseline or generic petroleum jelly works by “sealing” in whatever’s beneath it (serums, tonics, acids), creating a barrier between your skin and external stressors. This barrier also stops water from escaping from the skin (technically known as transepidermal water loss), which can be exacerbated in the winter due to central heating and weather.

Now, five years later, slugging is a mainstream option for people looking to repair and improve the healthy functioning of their skin barrier. Originally a Korean beauty ritual, slugging spans the gamut of treating dry, inflamed and sensitive skin. Users on TikTok extol the benefits of slugging, many say it “changed my skin” and helped deal with the fallout of retinol use (aka the retinol purge).

“Hand slugging” is the best way to repair dry, cracked skin, says Reddit