TL;DR
Slugging (a thick layer of petroleum jelly over your nighttime routine) was sold as universal barrier insurance from 2021 to 2023. The clinical bill came in 2024 to 2025: clogged-pore acne, fungal eruptions, ingredient occlusion that turned actives toxic, and a cohort of users in their late twenties with worse skin than they had in their teens. The audit: petrolatum is a legitimate tool for a narrow set of cases. Nightly use for years was always the wrong recommendation.
Slugging is the practice of sealing your nighttime skincare with a thick layer of petroleum jelly (Vaseline or Aquaphor) to create an occlusive film that prevents transepidermal water loss. The trend hit TikTok hard in 2021 and was sold as a barrier-repair miracle, particularly for the winter months. By 2023 it had been normalized into a nightly routine for a generation of users.
Three years later, the receipts are in. I have watched a cohort of users in their late twenties and early thirties present in dermatology offices with the kind of clogged-pore, fungal-acne, ingredient-trapped skin damage that older skincare professionals warned about in 2021. The trend producers moved on. The skin damage did not.
What slugging actually is
The mechanism is straightforward. Petroleum jelly is a hydrocarbon occlusive that forms a near-complete film on the skin surface. The film reduces transepidermal water loss by approximately 99 percent, according to the foundational 1980s research that established petrolatum as a benchmark occlusive. The skin underneath retains moisture; the surface stays soft and pliable.
In legitimate dermatological contexts, this is useful. Eczema flares, severely dry winter skin, post-procedure recovery (laser, microneedling, peels), wound healing on intact skin, and prevention of further water loss in compromised skin barrier conditions all benefit from occlusive use. Petrolatum is on the World Health Organization’s Essential Medicines List for a reason.
The therapeutic use case is narrow. The slugging trend universalized the practice.
The clinical bill
Three primary failure modes have shown up consistently in dermatology consultations.
First, comedogenic acne. Petroleum jelly itself is not comedogenic at the ingredient level, but it traps everything beneath it. Sebum, dead cells, makeup residue, the previous night’s serum, environmental dust. The trapped material occludes follicles. The result is non-inflammatory comedones (whiteheads, blackheads) and sometimes inflammatory acne in users who did not have it before. The pattern is most common on the forehead, cheeks, and chin.
Second, fungal acne (Malassezia folliculitis). The occlusive layer creates a warm, lipid-rich environment that is ideal for the lipophilic Malassezia yeast that normally lives on the skin in small numbers. Overgrowth produces a specific eruption: small, uniformly sized inflammatory papules, often itchy, typically on the forehead, hairline, chest, and upper back. A 2024 review in International Journal of Dermatology documented a rise in Malassezia folliculitis presentations in cosmetic dermatology clinics correlated with slugging adoption in the 18 to 35 demographic.
Third, ingredient occlusion turning actives toxic. Petroleum jelly applied over a retinoid increases the retinoid’s potency by trapping it against the skin under occlusion. Retinoid that was tolerable as a standalone became irritating, inflammatory, or actively damaging when slugged. The same applies to acids (glycolic, salicylic), benzoyl peroxide, and stronger anti-aging ingredients. Users who had tolerated their actives for years suddenly experienced peeling, redness, and barrier damage from the same actives because they added slugging on top.
Who profited
Petroleum jelly is a commodity. Vaseline (Unilever) and Aquaphor (Beiersdorf) saw modest sales increases during the slugging peak, but the products were already mass-market staples and the percentage growth was unspectacular. The bigger profit went elsewhere.
The trend created an entire ‘slugging-adjacent’ category. Boutique brands launched ‘slugging balms’ at $40 to $80 for a 30 ml jar of essentially repackaged petrolatum-and-emollient blends. Some added ‘skin-loving’ actives (ceramides, panthenol) that did not survive the occlusive carrier in any meaningful concentration. The pricing arbitrage was striking: a $5 tub of Vaseline producing the same effect as a $60 ‘overnight slugging treatment.’
The content creators profited heavily. Slugging was a perfect content format. A glossy face on camera, a ‘before and after’ shot taken in different lighting, an easy product mention. Sponsored videos for slugging balms ran across the platform from 2021 to 2023.
The retailers profited from the category expansion. Slugging balms, occlusive masks, ‘overnight glow’ products. The category itself was largely invented by the trend.
The contrarian take: three years of petrolatum has receipts
The damage pattern is visible in clinical settings now. The 26 to 31 year old cohort who started slugging in 2021 to 2022 are presenting in 2025 to 2026 with skin that is harder to treat than it should be for their age.
The specific pattern. Acne where there was no acne before. Pores visibly enlarged from years of follicular occlusion. A surface texture that reads as ‘damaged’ rather than ‘aged.’ Mild but persistent fungal eruptions that are misdiagnosed and mis-treated as bacterial acne. Reactive sensitivity from the slugging-plus-actives combination that destabilized the barrier in ways that have not fully reversed.
None of this is universal. Some users tolerated nightly slugging fine. The cohort that did not tolerate it is large enough to be visible in dermatology referral patterns, and the harm is real.
The dermatology professional community largely warned against universal slugging during the trend peak. The warnings were drowned out by content volume. Two years of TikTok endorsement outweighs one year of dermatologist op-eds in terms of consumer behavior.
Who actually still needs occlusives
The legitimate use cases for petrolatum did not disappear when the trend faded.
Eczema flares, particularly in winter, benefit from occlusion at the affected sites overnight. The use is targeted, not whole-face.
Severely dehydrated skin in arid environments or during specific events (long-haul flights, ski trips, desert exposure) benefits from short-term slugging. The use is episodic, not nightly.
Post-procedure recovery from professional treatments (microneedling, peels, laser, dermaplaning) typically includes a 48 to 72 hour occlusive recovery period. The use is supervised by a clinician and time-limited.
Hand and foot dryness, particularly in winter, is the classic petroleum jelly application. The use is targeted to body sites that are anatomically different from the face.
None of these use cases support ‘every night, on the whole face, for years.’
The fungal acne problem in detail
Malassezia folliculitis is the most under-diagnosed consequence of slugging. The presentation looks like acne. Most users assume it is acne. They treat it with benzoyl peroxide or salicylic acid, which do not work on yeast. The eruption persists. The user adds more slugging to ‘repair’ the irritated skin. The yeast thrives further.
The correct treatment is anti-fungal: ketoconazole shampoo used as a face wash for 5 to 10 minutes, applied two to three times weekly, often combined with discontinuation of the occlusive routine. The skin clears in three to six weeks. Most users only get to this point after seeing a dermatologist who recognizes the pattern.
The pattern recognition takes minutes for a trained eye. The trip to the dermatologist takes weeks to months. The trend produced a backlog of mis-treated fungal eruptions.
What replaced slugging
Ceramide-and-cholesterol moisturizers carry most of the legitimate barrier-repair share now. The CeraVe, Cicalfate, and First Aid Beauty product lines are the daily-use alternatives. The mechanism is different: instead of an occlusive film, the moisturizer delivers the lipids the skin uses to rebuild its own barrier.
For users who genuinely need additional water-loss prevention overnight (very dry climates, specific skin conditions), targeted petrolatum on the affected zones (corners of mouth, around nose, eyelids) is the dermatology-recommended replacement for whole-face slugging.
For broader context, see the slow skincare manifesto, the glass skin post-mortem, and the beef tallow critique.
FAQ
Can I slug occasionally? Yes. Once a week, on a very dry night, after a non-active routine. The harm is in nightly use.
Is petroleum jelly bad for me? No. It is one of the most thoroughly studied cosmetic ingredients in dermatology. The harm is contextual, not inherent.
How do I tell fungal acne from bacterial acne? Fungal acne is uniform in size (papules all roughly the same), tends to itch, clusters in lipid-rich zones (forehead, hairline, chest), and does not respond to standard acne treatments. A dermatologist can confirm with a simple visual exam.
If I stop slugging, will my skin recover? Mostly yes, over weeks to months. The fungal component clears with antifungal treatment. The follicular occlusion takes longer. The barrier sensitivity may persist.
What about slugging during winter only? Episodic seasonal use is closer to the legitimate use case. Even then, target the dry zones rather than the whole face.
Tag hub: More on barrier damage and recovery
Sources
Kim JH et al. Malassezia folliculitis in cosmetic dermatology. International Journal of Dermatology 2024. AAD position on occlusive use, 2023. WHO Model List of Essential Medicines, 2023 edition.