What does Vaseline actually do?

Petroleum jelly is an occlusive, meaning it forms a coating that slows water loss from your skin. It holds onto moisture already there rather than adding water, which is why applying it to damp skin makes sense. Vaseline is a useful moisturizer for dry skin, despite having the texture of a product that never left the prototype stage. A thicker coating is not necessary for facial use. There is no special strength to work up to: for slugging, choose pure petroleum jelly or a formula with very few additional ingredients.234

Use it on dry skin, lips, nails and areas that rub

  • For dry skin and lips, apply petroleum jelly while the skin is damp. Ointments are more effective and less irritating than lotions for dry skin.
  • For dry, flaky eyelids, use a small amount for moisture and protection. Eyelid skin is thin and easily irritated.
  • For nails and cuticles, apply it when they are damp, between polishes. This helps reduce brittleness and chipping.
  • For chafing prevention, apply it to places where skin rubs against skin or clothing, such as thighs or feet.
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How to apply it to dry skin

  1. 1Take a warm rather than hot bath or shower, using a gentle cleanser.
  2. 2Rinse well and gently pat your skin, leaving it damp.
  3. 3Apply the emollient to dry areas, ideally within three minutes of leaving the bath or shower.
  4. 4Rub it in gently. Reapply during the day when your skin feels dry.
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Plain emollients without active medicines can generally be used as needed and over the long term. Regular use helps soften dry, scaling skin and can help prevent cracks. If you use prescription creams, follow your prescriber's order of application: some medicines need to go on before the emollient. Do not introduce several new products together, because a reaction becomes harder to trace.3

Can you leave Vaseline on your face overnight?

An overnight coating, called slugging, can help dry skin retain moisture and allow its protective barrier to repair. It is more useful in dry winter weather than warm, humid weather. Skip slugging on oily skin, skin prone to acne, infected skin or open wounds. Avoid putting retinoids, alpha hydroxy acids or beta hydroxy acids underneath: trapping these ingredients beneath petroleum jelly can increase irritation.2

  1. 1Cleanse your face and apply your moisturizer.
  2. 2Apply a tiny amount of petroleum jelly, either across suitable dry skin or only on dry areas.
  3. 3Allow about 30 minutes before bed for your products to settle. A towel over your pillowcase can protect it.
  4. 4Leave the coating overnight, then wash your face in the morning.
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A full face coating is optional, so the name of the trend is doing more work than the routine requires. Slugging has no fixed schedule; a couple of nights can help during a dry spell, but it rarely needs to become a nightly routine. Stop and see a dermatologist if your skin becomes red or irritated.2

Use it to seal moisture into eczema prone skin

Petroleum jelly is an emollient, a skin softening ingredient, that helps seal moisture into skin affected by eczema. Applying Vaseline while your skin is still wet after a shower makes it easier to spread. Then towel off normally to remove some excess grease while leaving moisturizer on your skin. The greasy feel is a practical drawback, not a reason to apply it to completely dry skin. If eczema continues to interfere with your day or does not improve with home care, seek medical care rather than continuing to try home remedies. Nonprescription and prescription treatments are available.4

Use it during diaper changes

Keep your baby's skin clean and dry to help prevent diaper rash. If a rash develops, apply petroleum jelly at each diaper change. With appropriate care, the rash should clear in about three to four days. See a dermatologist if it persists.1

Use it on clean minor cuts and scrapes

Petroleum jelly keeps minor cuts, scrapes and scratches moist, helping prevent scabs that take longer to heal. It also helps limit how large, deep or itchy a scar becomes. Clean the wound daily; antibacterial ointments are not necessary for a minor wound kept clean this way. This is targeted wound care, not facial slugging over an open wound.1

After skin surgery, follow your wound care plan

Surgical wounds have their own instructions. A common plan is to keep the wound dry for 48 hours, remove the dressing, then apply Vaseline from a new pot. Leave adhesive wound strips in place to fall off by themselves. For curettage wounds, where skin has been scraped away, that plan specifies Vaseline once or twice daily for two to three weeks after the initial 48 hours. These wounds can take four to six weeks to heal. Contact your clinician if a wound becomes hot, swollen, sore or starts oozing. Diabetes or immune system problems can delay healing. For bleeding, apply pressure with a clean tissue for 10 minutes; seek medical advice if heavy bleeding does not stop.5

For a treated facial burn, keep healing skin moist

After a minor facial burn has been assessed and treated, petroleum jelly can keep exposed skin moist while it heals. Apply it three to four times daily until healed. Wash with water daily or before applying more ointment, and avoid perfumed soap. Do not smoke while using petroleum jelly. Burns elsewhere can require special dressings, so do not replace those with Vaseline. Contact the treating service for increasing pain, swelling, spreading redness, fever, a rash or feeling ill. A minor burn should heal within about two weeks; contact the service if it has not. Discoloration can last for months. Protect healed skin from sunlight with covering and high factor sunscreen for at least two summers.6

During fluorouracil treatment, use it as directed

Fluorouracil is a prescription cream used to treat certain sun damaged skin lesions. If treated skin becomes very sore or uncomfortable, stop the fluorouracil, bathe the area with water, dab dry and apply petroleum jelly daily. Use newly opened petroleum jelly kept free from fingertip contamination. Contact your prescriber if the reaction is severe or you are unsure whether to continue. Once the skin settles, you may be able to resume the prescribed course. This is care during a treatment reaction, not a reason to add Vaseline over every prescription cream.7

Where this answer comes from

  1. 15 ways to use petroleum jelly for skin careaad.org
  2. 2Slugging: Does This Skin Care Trend Work?health.clevelandclinic.org
  3. 3Emollients: Creams, Soaps, Moisturizers, Ointments, Benefitsmy.clevelandclinic.org
  4. 4The Best Home Remedies for Eczemahealth.clevelandclinic.org
  5. 5Wound care after skin surgerygloshospitals.nhs.uk
  6. 6Minor burns and scaldssouthtees.nhs.uk
  7. 75-fluorouracil creambad.org.uk