Maybe it's the cooler winter weather, or maybe it's just lockdown boredom, but slugging—the new, 21st-century name for "slathering your face in a thick layer of an occlusive substance like Vaseline"—has become a ubiquitous dry skincare trend on social media. "Slugging has recently taken off on social media, with the idea being that you apply a petrolatum based skincare product to the face before bedtime," says Harvard-trainer dermatologist Dr Christina Weng, founder of Mymiel. "Dermatologists have actually recommended this for a long time in various forms, most commonly for eczema or over wounds to encourage healing." While the practice has long been recommended by skincare experts such as dermatologists and aestheticians for protecting irritated skin and wounds, people have also been applying thick layers of cream or petrolatum to their faces for generations—Marilyn Monroe was famous for her generous daily use of Vaseline. But is it... good for you? Well, yes and maybe.