Educational information, not medical advice — ask your doctor or midwife.
Petroleum jelly is a purified, odorless, colorless semi-solid made from a blend of mineral waxes and oils derived from petroleum. It has been a staple in medicine cabinets and dermatology clinics for over 150 years, recognized by the FDA as a safe and effective over-the-counter skin protectant. Unlike many topical agents, it does not contain active drug molecules — its power comes entirely from its physical, barrier-forming properties.
Petroleum jelly works by forming a breathable yet highly occlusive layer on top of the skin that dramatically slows transepidermal water loss (TEWL) — the natural evaporation of moisture from the skin surface. It does not add moisture itself but traps existing water in the outermost skin layer, allowing the skin to hydrate and repair from within. This same occlusive effect also shields wounds and irritated skin from friction, bacteria, and environmental irritants while healing takes place.
Most commonly available as pure petroleum jelly in jars or tubes (e.g., Vaseline). Also found as a base ingredient in medicated wound ointments, lip balms, diaper rash creams, and moisturizing lotions. Medical-grade white petrolatum USP is used in clinical settings for post-procedure wound care and ophthalmologic ointments.
Petroleum jelly was discovered in 1859 by chemist Robert Chesebrough, who noticed oil workers using the residue from oil rigs to soothe cuts and burns. He refined and patented it, launching Vaseline in 1870. It was used in both World Wars as a field wound dressing and quickly became one of the most widely used dermatological products in history. Dermatologists today still consider it the gold standard occlusive moisturizer.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
Each grade below is for that condition specifically, not for Petroleum Jelly (Petrolatum) in general.
The 4 options with the best evidence for Diaper Rash, each with its grade and who should avoid it. One email.
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