Is slugging good for your skin, or just a trend?

The short answer: useful for dry skin, used occasionally

Slugging works best as an occasional fix. If your skin feels tight, flaky, or dehydrated, a thin layer of plain petrolatum at night can help hold water in. It is cheap, and it matters most in cold, dry months. Think of it as a sealant, not a treatment.

A Cleveland Clinic dermatologist makes the same case, noting it is more useful in winter and should rarely be a nightly routine, perhaps a couple of nights in a row when skin needs catching up (Cleveland Clinic on slugging). For the basics on application, see our slugging explainer.

What the research supports, and what it doesn't

The strongest evidence is for petrolatum itself, not the trend. In a 1992 study of human volunteers in the Journal of the American Academy of Dermatology, petrolatum did not slow barrier repair. It sped recovery after the barrier was disrupted with acetone, and the authors concluded it penetrates the outer skin layer rather than forming an impermeable film. The sample size was not in the abstract we retrieved.

Occlusion is also well documented. In a pig-ear model, petrolatum was the most occlusive base tested, cutting water loss to about 17% of its starting value right after application (hydrogel versus ointment comparison). That shows the physics of sealing, not a benefit in people.

A moisturizer review cites more than 98% less water loss at a 5% petrolatum concentration, but we could not trace that figure to its original study, so treat it cautiously (moisturizer review).

The best human data is about protection. In a 1997 study of 20 volunteers, petrolatum strongly protected skin against several irritants, including sodium lauryl sulfate and sodium hydroxide, during repeated exposure (Wigger-Alberti and Elsner, 1997). That supports a shield role, not a treatment for dryness.

Who should skip it

If your skin is oily or breakout-prone, be careful. The dermatologist quoted by Cleveland Clinic advises against slugging for oily, acne-prone, or infected skin.

The acne picture is messier. A 2024 JAAD review by Kamrani and colleagues, which covers petrolatum's safety and common myths, says its data dispel the idea that petrolatum causes acne (Kamrani et al. review). We read only the abstract. A clinical acne update adds that heavy occlusives can worsen acne (acne update). Petrolatum may not directly cause acne, but a thick layer can still be a poor match for acne-prone skin.

How to do it without causing trouble

• Use plain petrolatum, with at most minimal additives.
• Skip layering alpha hydroxy acids, beta hydroxy acids, and retinoids underneath, since they can irritate once trapped.
• Apply it over clean skin, and keep it to a couple of nights in a row before stopping.
• Check the ingredient list instead of trusting a 'non-comedogenic' label, since that phrase is not a regulated claim.

On safety, the MedlinePlus entry on petroleum jelly overdose mainly covers swallowing it or getting it in the eyes. Large amounts on skin can irritate, and if the product reaches the airway it is a risk. That page is not a safety study of slugging, so keep the layer thin (MedlinePlus).

What we still don't know

Several gaps remain. No study we found tests how often or how long slugging should last, how it compares with ordinary occlusive moisturizers, or what happens in people with acne. The most authoritative routine guidance we found is a single dermatologist quoted by a health-system website, not a peer-reviewed study.

If you want the next layer of evidence, the full text of the 2024 JAAD review would show whether it addresses slugging directly and what its comedogenicity data actually says.