Slugging, gua sha, snail mucin: should you bother?

The world of skincare is driven by trends that go viral before a single study is finished. Slugging, gua sha and snail mucin are three of them: billions of views, fervent enthusiasm – but how much evidence actually lies behind them? The answer varies by trend, and the nuances are worth understanding.

Slugging: the hype is half right

Slugging – covering your face overnight with a thin layer of petroleum jelly – does have a real mechanism behind it. Petroleum jelly acts as a sealing layer that noticeably reduces moisture loss, and it does so demonstrably better than plant-based oils. So far, so good. But the claims go further: slugging is said to heal dry skin and repair a damaged skin barrier. That is where things get complicated. Petroleum jelly retains existing moisture; it adds nothing of its own. If you want to structurally improve dry skin, you need a moisturiser containing ceramides or urea that actively supports the barrier. Slugging works best as a complement to that kind of cream, not as a replacement. A note for anyone over 40: after your fortieth birthday your skin produces fewer of its own lipids, which makes barrier support through ceramides more relevant than occlusion alone.

Gua sha works – just not the way most people think

Gua sha is sold as an all-in-one solution: a tighter face, fewer wrinkles, better lymphatic drainage. The evidence is more nuanced than that. Small studies show that gua sha relaxes facial muscles and improves contours – a real effect you can see. But for skin laxity and elasticity, electric combination devices perform better, and even a regular facial roller scores higher on those measures. The evidence comes from a limited number of smaller studies, so certainties are still lacking. What you can reasonably expect: relaxation and a temporarily improved appearance, not structural collagen rebuilding. If you use gua sha as a moment of calm in an evening routine, it delivers on that goal.

Snail mucin: biologically interesting, clinically unfinished

Snail mucin is the ingredient with the biggest gap between expectation and evidence. Lab and cell studies show that it activates fibroblasts, protects skin cells and may play a role in hydration and scar recovery. That is a serious biological foundation. But clinical evidence in humans is largely still missing: the studies are small, there are no quality standards for the concentration of the ingredient in products, and allergy research has barely been done. Whether snail mucin helps with scarring has not yet been shown in humans, even though the laboratory signals are promising. You can try it cautiously, but with two caveats: you do not know how much active ingredient is actually in your product, and skin reactions are a real risk if your skin is sensitive.

Skin cycling: the schedule probably adds nothing

Skin cycling – alternating active ingredients such as retinol and exfoliants across several nights – has not been studied as a method. The individual ingredients that tend to appear in these routines, such as ceramides and urea, do have a reasonable scientific basis for barrier repair. But whether the alternating schedule itself adds anything over a consistent routine has not been studied. If you already use a good moisturising cream, the schedule most likely adds nothing.

Two factors that matter more than any trend

Sleep deprivation measurably affects hydration, elasticity and wrinkle formation – even after a single bad night. Urban pollution accelerates skin ageing through free radicals and collagen breakdown, and the combination with sun exposure is the most damaging of all. Both factors have more well-supported impact than most trending products. Good sun protection and consistently getting enough sleep are therefore the most concrete things you can do, alongside a moisturising routine built on ceramides. Trends are a supplement, not a substitute.