Does slugging work? For dry, tight skin, mostly yes. A thin layer of petrolatum as the last step cuts water loss through the skin and, in human studies, sped up barrier repair rather than blocking it. A 2024 dermatology review rejects the idea that petrolatum causes acne. Avoid slugging over retinoids or acids, because sealing them in can increase absorption.
The heating comes on in October, and by the second week your face feels tight before you have even finished brushing your teeth. Moisturizer helps for an hour. Slugging promises to make it last all night: a thin layer of petroleum jelly as the very last step, so you wake up with skin that still feels soft. So, does slugging work? For dry, tight skin, the research says mostly yes, with a few situations where it is better to skip it.
What is slugging?
Slugging means applying a thin layer of an occlusive, usually petrolatum (petroleum jelly), over your usual evening routine and leaving it on overnight. The name is new; the idea is not. Occlusives work by forming a layer that slows water evaporating from the skin, unlike humectants such as glycerin, which pull water into the skin’s outer layer. Our guide to humectant vs occlusive skincare explains how the two work together in winter.
Our comparison of sleeping packs and night creams explains how those two kinds of ingredient share the work in most moisturizers.
Does slugging actually work for dry skin?
Yes, in the sense that petrolatum measurably cuts water loss through the skin. In a 2025 randomized study at the University of Granada in Spain, 54 adults applied petrolatum and olive oil to their forearms. Both raised skin hydration and lowered redness, and “Petrolatum additionally reduced TEWL”, TEWL being the water lost through the skin.
A 2022 Brazilian study of 80 women measured water loss 15 minutes, 2 hours and 6 hours after applying petrolatum or plant oils. Petrolatum gave the strongest seal right away; most oils caught up over the 6 hours. That is part of why petrolatum is the usual slugging choice: it works from the moment it goes on.
A 2020 French trial in 51 people with dry skin tested a cream combining glycerin and petrolatum over 12 hours. The petrolatum part reduced water loss, and the glycerin part improved hydration. One of its authors worked for the cream’s manufacturer. Together the results support the slugging order: a hydrating product first, petrolatum on top.
Does slugging stop your skin from repairing itself?
No. This is the most common worry, that a heavy layer suffocates skin, and the evidence points the other way. In a 1992 US study, researchers damaged the skin barrier of volunteers and then compared patches treated with petroleum jelly to untreated ones. Petroleum jelly “accelerated, rather than impeded, barrier recovery”. Under the microscope, it did not sit on top like plastic wrap; it “permeates throughout the SC interstices”, the spaces between cells in the outer layer, “allowing normal barrier recovery despite its occlusive properties”.
Does slugging clog pores?
Petrolatum itself is unlikely to be the problem. A 2024 review of petroleum jelly in the Journal of the American Academy of Dermatology reviews the data on its safety, including whether it causes acne, “dispelling misconceptions about petrolatum use around oxygen and as a cause of acne”.
What you seal underneath matters more. Slugging over a heavy, oily cream is not the same as slugging over a light moisturizer. If you get breakouts easily, try it on the driest areas first, such as around the mouth and on the cheeks, and stop if new bumps appear.
Can you slug over retinol or acids?
It is better not to, at least when you are starting. A review of skin occlusion from the University of California, San Francisco notes that covering skin “often, but not always, increases percutaneous absorption of applied chemicals”, meaning more of what is underneath gets into the skin. With a retinoid or an exfoliating acid, more absorption can mean more irritation.
Keep slugging for the nights you skip actives. If you follow a skin cycling schedule, the recovery nights are the natural fit.
How do you slug properly?
- Cleanse, then apply your usual hydrating serum or moisturizer.
- Take a pea-sized amount of petrolatum, warm it between your fingertips and press a thin layer over the dry areas or the whole face.
- Use an old pillowcase, since some will transfer.
- Wash it off in the morning with your normal cleanser.
If tightness is a year-round problem, our routine for dry skin covers what to change during the day too.
Editor’s note
I use the same idea on my hands and feet rather than my face. When my hands are dry, cracked and burning, I put a thick layer of Bepanthen ointment or the lotion from my dermatologist on them, pull on plastic gloves and sleep in them; by morning my hands are fully moisturized. When the season changes and my heels feel like they might crack, I put body lotion on my feet, cover them with a plastic bag, add bed socks on top and sleep. In the morning they are very soft. More on both in dry, cracked hands in winter and how to get rid of cracked heels.
This article is for general cosmetic information and is not medical advice.
Evidence: Support comes from small human studies of petrolatum on water loss and barrier recovery (51 to 80 people) and dermatology reviews; there are no trials of slugging as a nightly facial routine.
Does slugging clog pores?
Petrolatum itself is not a known cause of breakouts. A 2024 review in the Journal of the American Academy of Dermatology addresses that worry directly and calls the idea of petrolatum causing acne a misconception. What it seals in is another matter, so use it over a simple moisturizer, not over a heavy or pore-clogging product.
Can you slug over retinol?
It is better not to, at least at first. Sealing the skin under a layer often increases how much of the product underneath gets absorbed, which can make a retinoid or acid more irritating. Use slugging on nights you skip them.
How often should you slug?
No study sets a frequency. Start with a few nights a week when your skin feels tight, and cut back if it feels greasy or you notice new breakouts.
Is slugging good for oily skin?
Usually not needed. Slugging is aimed at water loss and tightness. If your skin is oily but dehydrated, a lighter moisturizer is a better first step.
- Ghadially R, Halkier-Sorensen L, Elias PM. Effects of petrolatum on stratum corneum structure and function. J Am Acad Dermatol. 1992;26(3 Pt 2):387-96.
- Kamrani P, et al. Petroleum jelly: a comprehensive review of its history, uses, and safety. J Am Acad Dermatol. 2024;90(4):807-813.
- Zhai H, Maibach HI. Effects of skin occlusion on percutaneous absorption: an overview. Skin Pharmacol Appl Skin Physiol. 2001;14(1):1-10.
- Rubio-Santoyo A, et al. Effects of extra virgin olive oil and petrolatum on skin barrier function and microtopography. J Clin Med. 2025;14(13):4675.
- Pinto JR, et al. Skin occlusive performance: sustainable alternatives for petrolatum in skincare formulations. J Cosmet Dermatol. 2022;21(10):4775-4780.
- Vaillant L, et al. Combined effects of glycerol and petrolatum in an emollient cream: a randomized, double-blind, crossover study in healthy volunteers with dry skin. J Cosmet Dermatol. 2020;19(6):1399-1403.
Editorial content, not medical advice.
