Petroleum jelly is one of the most versatile and effective skin protectants available, useful for everything from healing minor wounds to preventing chafing during a marathon. It works by forming a semi-occlusive barrier on the skin’s surface that locks in moisture, reducing water loss through the skin by roughly 98%. That’s far more effective than other oil-based moisturizers, which typically reduce water loss by only 20% to 30%.
Wound Healing and Scar Prevention
One of the best-supported uses for petroleum jelly is keeping minor cuts, scrapes, and scratches moist while they heal. The American Academy of Dermatology recommends applying it to cleaned wounds daily. A moist wound heals faster than a dry one because it avoids forming a thick scab, which actually slows the regeneration of new skin cells. Keeping the wound environment moist also helps prevent scars from becoming too large, deep, or itchy.
You don’t need antibiotic ointment for most minor injuries. As long as you’re cleaning the wound each day, plain petroleum jelly provides the protective barrier your skin needs to repair itself. This also applies after minor surgical procedures or stitches, where keeping the site moisturized supports recovery.
Eczema and Dry Skin Conditions
Petroleum jelly does more than just sit on the skin’s surface. Research published in the Journal of Allergy and Clinical Immunology found that applying petrolatum to skin affected by atopic dermatitis (eczema) triggered the production of key proteins the skin uses to build and maintain its protective barrier. It also increased the thickness of the outermost skin layer and reduced the immune cell activity that drives eczema flare-ups, even in patches of skin that appeared normal but harbored underlying barrier defects.
For people with eczema or chronically dry skin, this makes petroleum jelly a surprisingly active treatment despite its reputation as an “inert” substance. It’s inexpensive, widely available, and rarely causes allergic reactions, which matters when your skin is already irritated and reactive.
Diaper Rash Protection
Petroleum jelly works well as a preventive barrier against diaper rash. Applied to clean, dry skin, it creates a layer that shields against moisture and irritants from prolonged diaper contact. A clinical trial of 268 infants found that diapers designed to continuously deliver a zinc oxide and petrolatum formula to the skin significantly reduced redness and diaper rash compared to identical diapers without the formula. The zinc oxide and petrolatum combination reduced skin barrier damage by up to 3.5 times in adult skin irritation tests.
For mild rash prevention, petroleum jelly alone is often enough. If redness or irritation has already developed, a product combining zinc oxide with petrolatum provides stronger protection because zinc oxide has additional soothing and drying properties.
Slugging for Overnight Skin Repair
Slugging, the practice of applying a thin layer of petroleum jelly over your face before bed, has become a popular skincare technique for good reason. If your skin is dehydrated or your skin barrier is damaged from harsh weather, overwashing, or irritating products, a coating of petroleum jelly overnight prevents further water loss and gives your skin time to repair.
That said, slugging isn’t for everyone. Dermatologists at the Cleveland Clinic advise against it if you have oily or acne-prone skin, since those skin types already have a sufficient (or excessive) lipid layer. Adding petroleum jelly on top provides no benefit and can make things worse. You should also avoid trapping active ingredients like retinoids, alpha hydroxy acids, or beta hydroxy acids under the petroleum jelly layer. These can irritate skin when sealed in. If you do slug, a gentle foaming cleanser in the morning works best to remove the residue.
Does Petroleum Jelly Clog Pores?
The belief that petroleum jelly clogs pores is widespread but not well supported. A comprehensive review in the Journal of the American Academy of Dermatology found that while several sources claim petrolatum is comedogenic, none provided references to back the claim. The concern traces back to early studies where petrolatum was applied continuously under occlusion (sealed tightly against the skin) for six weeks, which did produce mild comedogenicity. But follow-up work by the same researchers actually found that petrolatum improved acne papules. Used normally, without airtight occlusion, petroleum jelly is considered noncomedogenic.
Chafing and Friction Prevention
Distance runners, hikers, and anyone who deals with skin-on-skin friction knows petroleum jelly as a go-to lubricant. Applied to inner thighs, underarms, nipples, or the tops of feet before activity, it lets skin surfaces glide past each other instead of catching and pulling. This is especially useful during long runs or in hot, humid conditions where sweat can make friction worse. A thin layer before exercise is usually enough, though longer activities may require reapplication at rest stops.
Lip and Cuticle Care
Petroleum jelly is effective for cracked lips and dry cuticles for the same reason it works on the rest of your skin: it seals in existing moisture. For lips, which lack oil glands and dry out quickly, a layer of petroleum jelly acts as a substitute barrier. For cuticles, applying it before bed softens the skin around the nails and can reduce hangnails and cracking over time.
One Risk Worth Knowing
There is one situation where petroleum jelly can cause harm. Applying it inside the nose over long periods can, in rare cases, lead to lipoid pneumonia. Small amounts of the jelly can travel into the windpipe and lungs, and over many months, this buildup causes inflammation. Symptoms include cough, chest pain, or shortness of breath, though some people show no symptoms at all and the condition is only discovered on a chest X-ray. The Mayo Clinic notes this is rare, but it’s worth choosing a water-based nasal spray or saline gel instead if you regularly deal with a dry nose.
Storage and Shelf Life
Petroleum jelly has a shelf life of two to three years when stored properly. Keep it in its original container, away from heat and direct sunlight. Bathrooms, despite being the most common storage spot, tend to expose it to temperature swings and humidity. After the expiration date, petroleum jelly typically remains safe to use, but watch for cloudiness, separation, unusual texture, or discoloration. Thickening over time is normal and doesn’t indicate spoilage.