Slugging: Does Vaseline on Your Face Actually Work?

What Is Slugging?

Slugging is the practice of applying a thin layer of petrolatum — most commonly plain Vaseline petroleum jelly or a petrolatum-containing ointment — as the final step of your PM skincare routine. The name comes from the appearance: the thick, glossy coating makes skin look shiny, like a slug's trail.

Despite being elevated to a viral skincare trend in the early 2020s, slugging is not new. Petrolatum has been used in dermatology for wound healing, post-procedure skin protection, and barrier repair for well over a century. Black American skincare traditions used Vaseline as a moisture-locking overnight treatment for generations before it had a hashtag. What the trend did was bring mainstream attention to an underutilized and evidence-backed technique.

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How Slugging Works: The Science

Slugging's mechanism is occlusion. Petrolatum is hydrophobic — water-repelling — and when applied to skin, it forms a dense hydrophobic film on the stratum corneum surface. This film dramatically reduces the rate of transepidermal water loss (TEWL), the passive evaporation of water through the epidermis that continues even during sleep.

The clinical data are clear: A 2024 comprehensive review in the Journal of the American Academy of Dermatology confirmed petrolatum reduces TEWL by approximately 46% within 40 minutes of application — compared with approximately 16% for ordinary low-lipid and high-lipid creams. No other OTC ingredient matches this level of occlusion.

What petrolatum does NOT do:

• It does not add water to the skin
• It does not repair the lipid barrier (it seals it, not restores it)
• It does not supply humectants that draw water in
• It does not penetrate the skin (its molecules are too large)

This is why slugging must be done on top of a complete skincare routine — ideally including a humectant (glycerin or hyaluronic acid) and a ceramide-containing moisturizer. The petrolatum seals what is already there. Applied to bare, unwashed skin, it seals in whatever is on the surface — including makeup residue, pollutants, and bacteria.

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Does Vaseline Cause Acne?

This is the most persistent concern — and the clinical answer is no.

The misconception arose because petrolatum is occlusive, and occlusion is often associated with pore clogging. But petrolatum's molecular weight is too high to enter follicular openings. Controlled patch testing and clinical evaluation, including the comprehensive 2024 JAAD review, consistently show petrolatum does not increase comedones when applied to cleansed skin.

The real concern is context, not the ingredient: If you apply petrolatum over skin that still has residual comedogenic ingredients (from makeup, heavy oils, or actives applied without full absorption), the occlusion seals in those ingredients and increases their contact time with the skin. The petrolatum is not causing the congestion; the inadequate cleanse beneath it is.

The practical rule: if you are acne-prone, ensure a thorough double cleanse (oil cleanser to remove residue, then a gentle cream cleanser) before slugging, and trial with a small area first. If you are actively breaking out in cystic or inflamed acne, skip slugging on those areas entirely until the flare resolves.

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Vaseline vs. Aquaphor: Which Should You Use?

Recommendation: For pure slugging as an occlusive seal over a complete routine, either works. For sensitive or eczema-prone skin, pure petrolatum (Vaseline) eliminates the lanolin allergy risk. For those who want an all-in-one overnight ointment without a separate moisturizer step, Aquaphor's combined formulation is convenient.

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Who Should Slug (and Who Shouldn't)

Ideal Candidates

• Dry skin type — chronically lipid-deficient skin that benefits from maximum overnight moisture retention.
• Dehydrated skin — any skin type experiencing transient low stratum corneum water content; slugging prevents overnight TEWL from worsening the condition.
• Compromised or inflamed barrier — skin recovering from over-exfoliation, retinoid irritation, windburn, sunburn, or post-procedure (consult your clinician first for post-procedure use).
• Mature skin — sebum production declines with age; slugging compensates for reduced natural occlusion.
• Cold, dry environments — winter slugging is particularly effective when low humidity and heating maximize TEWL overnight.

Proceed with Caution

• Acne-prone skin — trial on a small area; ensure thorough cleansing beneath. Avoid over active breakouts.
• Oily skin — the added occlusion is likely unnecessary and may feel uncomfortable; not harmful but not beneficial either.
• Rosacea — the occlusive environment can occasionally worsen flushing; test on a small area.
• Sensitive skin with fragrance sensitivities — ensure the petrolatum is pure; avoid Aquaphor if lanolin-sensitized.

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How to Slug: Step-by-Step Protocol

See the steps section below for the ordered protocol. Key principles:

The technique lives and dies on what goes underneath. A proper cleanse before slugging is essential. Slugging over makeup, SPF residue, or comedogenic products amplifies those residues rather than just locking in moisture.

Less is more. A thin layer — enough to make the skin look shiny — is sufficient. A thick coating does not improve occlusion meaningfully and is wasteful, uncomfortable, and potentially more occluding than desired for congestion-prone skin.

Do not rub in. Pat the petrolatum gently onto the skin. Aggressive rubbing creates friction and drags product without improving distribution.

Time your actives correctly. If using retinol or AHAs on slugging nights, apply them before the petrolatum layer in your normal routine sequence. Note: slugging on top of retinol can increase retinol absorption (the occlusion drives deeper penetration). This can increase irritation — especially for retinol beginners. On retinol nights, allow retinol to fully absorb (20–30 minutes) before applying petrolatum, or apply petrolatum on alternate nights only.

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Common Mistakes

Slugging without cleansing: Petrolatum seals whatever is on the surface — makeup, SPF, pollution, bacteria. Always cleanse first.

Using fragrance-containing petroleum jelly variations: Some branded products labelled as "petroleum jelly" contain fragrance or added ingredients. For pure slugging, check that the only ingredient is petrolatum (white petrolatum USP).

Using too much: A smear the width of a fingernail, spread thin across the face, is enough. Globs of petrolatum do not improve efficacy and result in product transfer onto pillowcases.

Expecting immediate hydration: Petrolatum is an occlusive, not a humectant. It does not feel immediately hydrating the way glycerin does. Its benefit is measured the next morning, when overnight TEWL reduction is visible as less tight, more supple skin.

Slugging with fresh retinoid wounds or open skin: Petrolatum amplifies penetration. Broken skin, active eczema lesions, or inflamed acne lesions should not be slugged without clinical guidance.

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What to Put Under the Slug

For maximum slugging benefit, the routine beneath should include:

1. Double cleanse (oil cleanser then cream cleanser) — ensures a clean surface for the occlusive.
2. Humectant serum (glycerin or hyaluronic acid on slightly damp skin) — draws water into the stratum corneum that the petrolatum will then seal in.
3. Ceramide-containing moisturizer — addresses the lipid deficit beneath the occlusive layer. See Best Moisturizer for Dry Skin for formula guidance.
4. Any active treatments (retinol, niacinamide — allow full absorption first).
5. Thin petrolatum layer as the final step.

This layered approach — humectant → emollient → occlusive — replicates the functional anatomy of a healthy stratum corneum and is the basis of what dermatologists call the "soak and seal" technique for dry skin and eczema management.

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How Often Should You Slug?

• Dry skin in winter: Nightly is well-tolerated and beneficial.
• Dry skin in summer: 2–3 nights per week; summer humidity reduces the TEWL differential.
• Dehydrated or compromised barrier: Nightly until barrier stabilizes, then as needed.
• General maintenance: 1–3 nights per week as a hydration supplement to a normal routine.

There is no clinical evidence of harm from nightly petrolatum use on cleansed skin. The only reasons to reduce frequency are personal comfort (texture, pillowcase concerns) and the congestion-caution for acne-prone users.