Is Slugging Good for Your Skin? Not With Retinol Under It

Slugging is worth trying if your skin is dry, tight or raw from cold weather or too much exfoliating. Skip it on nights you use a retinoid or an acid. If you break out easily, keep it off your face, because the seal holds in whatever sits underneath.

Maybe your face feels tight by mid-morning however much cream you use, and the petroleum jelly videos look tempting. Or you tried it once and woke up with new bumps. Both results make sense once you know what the layer does, and what you put under it decides which one you get.

What Is Slugging, and Why Does It Work?

Slugging means finishing your night routine with a thin coat of petroleum jelly, so your skin loses less water while you sleep. It doesn't add water. It slows down the water that's already leaving.

Petroleum jelly is unusually good at this. A 2016 review in the Indian Journal of Dermatology says petrolatum at 5% or more reduces water loss through the skin by more than 98%. It puts lanolin, mineral oil and silicones at only 20 to 30%. The same review gives petroleum jelly 170 times the water vapor resistance of olive oil.

It also seems to help the barrier mend, rather than just sitting on top. In a 1992 study, researchers damaged the skin barrier of human volunteers with acetone. Petroleum jelly accelerated, rather than impeded, barrier recovery, and it spread into the gaps between cells in the outer layer.

A later study in the Journal of Allergy and Clinical Immunology covered 36 healthy volunteers and 13 people with moderate eczema. Skin kept under petrolatum showed higher levels of the barrier proteins filaggrin and loricrin, plus more of the skin's own antimicrobial proteins. None of this research tested slugging on the face as a nightly trend. Treat it as the reason the idea works, not proof of the routine.

Is Slugging Good for Dry Skin?

Yes, it's the skin it suits best. Cleveland Clinic dermatologist Amy Kassouf says slugging may help skin that is feeling dry and dehydrated. She adds that it's more likely to help in dry winter months, and less necessary when it's warm and humid.

A University of Colorado dermatologist says the people who benefit most live in dry climates or have dry skin. In hot, humid weather it may feel too heavy.

Put it over moisture, not on dry skin. The AAD advises applying petroleum jelly when your skin is damp, and its dermatologists suggest putting it on top of a lotion or cream. On deeper skin tones, dryness often shows up as a whitish or grayish cast, often called ashy skin. AAD dermatologists say a moisturizer with ceramides can reduce that look.

If your barrier is actively damaged, slugging is one step, not the whole fix. How to repair a damaged skin barrier covers what to stop first and how long repair takes. If you can't tell whether you're dry or just dehydrated, dry or dehydrated skin explains the difference.

Can You Slug Over Retinol or Acids?

Not on the same night. A seal over an active ingredient can push more of it into your skin, which can make it more irritating.

A 2001 review from the University of California, San Francisco notes that occlusion often, but not always, increases how much of an applied chemical gets absorbed. Cleveland Clinic's advice fits with that. Don't trap alpha hydroxy acids, beta hydroxy acids or retinoids under the layer, because they can irritate your skin.

This is the most common way slugging goes wrong. Your retinoid was tolerable on its own, then a sealed night leaves you red, stinging and peeling. The product didn't change, but the dose reaching your skin may have.

Here's how to sort what goes under the layer:

• Fine to seal: a plain, fragrance-free moisturizer, or a simple hydrating serum you already tolerate.
• Use on a different night: retinoids such as retinol, tretinoin and adapalene, plus glycolic, lactic and salicylic acids.
• Ask first: anything prescribed, such as a steroid or acne cream. Your prescriber can tell you whether covering it is safe.

If you're still building up to a retinoid, using retinol on dark skin covers how to start slowly without irritation.

Does Slugging Cause Acne?

It can, if you're prone to breakouts. The AAD says to avoid petroleum jelly on your face if you're acne-prone, because it may cause breakouts in some people. Cleveland Clinic says slugging could make acne worse, and that oily skin already has enough of its own lipid layer.

Fungal acne is another reason to skip it. This condition, properly called Malassezia folliculitis, is a yeast overgrowth in the hair follicles. A 2014 case report and review notes that occlusive make-up, lotion, or sunscreens may also promote flares. It's often mistaken for regular acne.

The clues are small, uniform bumps that itch, no blackheads, and acne that doesn't clear with usual acne treatment. If that sounds like yours, a dermatologist can confirm it. Until then, slugging may make it flare.

Why a Breakout From Slugging Costs More on Darker Skin

On brown and Black skin, a breakout often leaves a mark that outlasts it. The AAD says these dark spots can last much longer than the acne itself. That makes a week of sealed-in bumps a bigger price to pay.

Hair oil makes it riskier. The AAD calls forehead and temple breakouts from oily hair products pomade acne. It also warns that cocoa butter and shea butter can clog pores. If you oil your hair or edges at night, both products can end up on your forehead and pillowcase.

• If your skin isn't acne-prone, slug only your driest areas, such as your cheeks, and keep it away from your hairline.
• Wash your pillowcase often. The AAD's advice for hair-product breakouts is to wash everything your head touched, including pillowcases, caps and headbands.
• If you break out, stop. The AAD says hair-product acne can take 4 to 6 weeks to clear after you remove the cause.

If marks are already there, why acne marks last longer on dark skin covers what fades them.

How to Slug Without the Downsides

• Start clean. Cleveland Clinic says slugging should only be done on clean skin.
• Moisturize first. Apply a plain cream while your skin is still slightly damp.
• Use very little. A thin layer is enough. Focus on the driest areas, such as the cheeks, lips and eyelids. If you're acne-prone, keep it to your lips.
• Don't make it nightly. Cleveland Clinic suggests using it as needed, perhaps a couple of nights in a row to catch up, and rarely every night.
• Wash it off in the morning. Then go on with your usual routine and sunscreen.

Don't slug over an open wound or skin that looks infected. Cleveland Clinic warns the layer may stop an infection from clearing.

Slugging or Skin Flooding?

They solve different halves of the same problem. Skin flooding layers water-attracting serums on damp skin, while slugging seals moisture in. The 2016 review notes that humectants are usually paired with an occlusive, because on their own they can increase water loss. Skin flooding covers the layering side.

When to See a Doctor About Dry Skin

See a dermatologist if your skin stays dry, rough or itchy despite a gentle routine. The AAD notes that persistent dryness can be an undiagnosed condition such as eczema, ichthyosis or psoriasis. On darker skin these can go unrecognized for years.

Also book an appointment if slugging leaves you red or irritated, if itchy bumps don't respond to acne products, or if skin looks infected. A thicker seal won't treat a skin condition.

Frequently Asked Questions

Does Vaseline Clog Your Pores?

Petroleum jelly doesn't cause breakouts for everyone, but it can for some people. The AAD advises keeping it off your face if you're acne-prone. If you break out easily, keep it off your face. Use it on your lips or on dry patches on your body instead.

Can You Slug Every Night?

Cleveland Clinic suggests it should rarely be a nightly habit. Use it when your skin feels dry, for example a few nights in a row during winter, then go back to your usual routine.

Can You Slug With Something Other Than Petroleum Jelly?

You can, but it won't seal as well. The 2016 review found lanolin, mineral oil and silicones cut water loss by only 20 to 30%. AAD dermatologists also note that butters and oils tend to melt on the skin, so they work less well as moisturizers.