Vaseline, or petroleum jelly, is one of the most versatile skin care products you can own. It works as an occlusive, meaning it forms a protective layer on the skin’s surface that prevents water from evaporating. That single mechanism makes it useful for everything from healing minor cuts to protecting against chafing during a marathon.
How Petroleum Jelly Works on Skin
Your skin constantly loses moisture through evaporation, a process called transepidermal water loss. Petroleum jelly sits on the surface and acts like a physical seal, trapping that moisture underneath. This retained hydration fills the outer layer of skin like a sponge, making it thicker, more pliable, and more elastic. At the same time, that barrier keeps irritants and allergens from getting in.
Because petroleum jelly is chemically similar to proteins already in your skin, it rarely causes allergic reactions. It’s also non-comedogenic, meaning it doesn’t clog pores on its own. That said, it can trap other products underneath it, so what you apply before petroleum jelly matters.
Wound Healing and Scar Prevention
The American Academy of Dermatology recommends petroleum jelly for minor cuts, scrapes, and scratches. Applying it keeps the wound moist, which prevents it from drying out and forming a scab. This is a good thing: wounds that scab over actually take longer to heal than wounds kept moist. A moist environment also helps prevent scars from becoming too large, deep, or itchy.
You don’t need antibiotic ointment for most minor wounds. As long as you clean the area daily and reapply petroleum jelly, a plain layer of Vaseline does the job. This makes it a practical, inexpensive first-aid staple.
Dry Skin, Eczema, and Cracked Skin
Petroleum jelly is one of the most effective moisturizers for severely dry or dehydrated skin. It doesn’t add water to your skin, but it prevents the water already there from escaping. For people with eczema or other conditions where the skin barrier is compromised, that protection can reduce irritation and help the skin repair itself overnight.
It works well on specific trouble spots too. Dermatologists recommend it for chapped lips, dry cuticles, cracked heels, and rough hands. Because it’s so gentle, it’s also a go-to treatment for eyelid dermatitis, where many other creams and lotions contain fragrances or preservatives that make things worse.
Slugging for Overnight Hydration
Slugging is the practice of applying a thin layer of petroleum jelly over your entire face at night as the last step in your skin care routine. The name comes from the shiny, slug-like appearance it gives your skin. Dermatologists at the Cleveland Clinic say it can genuinely help if your skin is dehydrated, parched, or damaged from harsh weather.
The technique works best in dry winter months and is less necessary when humidity is higher. You may need to slug a couple nights in a row when your skin is especially dry, but it rarely needs to become a nightly habit. A few groups should skip it entirely:
- Oily skin: Skin that already produces plenty of oil has an adequate lipid layer and doesn’t benefit from adding more.
- Acne-prone skin: While petroleum jelly itself is non-comedogenic, the occlusive barrier can trap oils and other products against the skin, potentially making breakouts worse.
- Active skin care acids or retinoids: Products containing alpha hydroxy acids, beta hydroxy acids, or retinoids can become more irritating when sealed under petroleum jelly. Use these on nights you don’t slug.
Chafing and Blister Prevention
Runners, cyclists, and triathletes have used petroleum jelly for decades to reduce friction during long workouts. It creates a slick barrier between skin and clothing, or between two surfaces of skin that rub together. The most common areas to apply it include the inner thighs, heels, toes, the ball of the foot, underarms, the neck (especially under wetsuit collars), and anywhere a sports bra or waistband sits against the body.
It’s affordable and effective for this purpose, though it is greasy. Some athletes prefer specialized anti-chafe balms for longer events, but for most people, a jar of Vaseline handles the job.
Diaper Rash Prevention
Petroleum jelly is commonly used as a barrier cream during diaper changes. A randomized clinical trial at Donostia University Hospital in Spain found a lower incidence of diaper rash among newborns treated with petroleum jelly (17.1%) compared to a control group (22.2%), though the difference wasn’t large enough to be statistically significant. Still, it serves as a simple, fragrance-free option for creating a moisture barrier between a baby’s skin and the irritants in a wet diaper. The same study found that antibiotic use and frequent stools increased diaper rash risk, while breastfeeding appeared to be protective.
Safety and Purity
Not all petroleum jelly products are created equal. The concern with petroleum-based products has always been polycyclic aromatic hydrocarbons (PAHs), which are potentially harmful compounds that can exist in less refined petroleum products. Pharmaceutical-grade petroleum jelly, labeled as “White Petrolatum USP,” is refined to meet strict purity standards. The United States Pharmacopeia has added specific testing for these compounds to its updated monograph, ensuring that USP-grade products are screened for them.
If you’re buying Vaseline or a store-brand equivalent, look for the USP designation on the label. This tells you it meets the refining standards needed to be safe for skin application. Unbranded or industrial petroleum jelly may not meet the same criteria.