Petrolatum and Mineral Oil
Highly refined, petroleum-derived occlusives that seal moisture in and protect very dry or compromised skin.
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Dry & dehydrated skin · Barrier support · Sensitive skin
What it does
Petrolatum, or petroleum jelly, and mineral oil are among the most effective occlusives in skincare. They sit on the surface and form a protective seal that slows water loss, keeping skin softer and more comfortable. MG's Notes recommend them for very dry or compromised skin, in winter, on long-haul flights and on dry areas of the body, and, in bland, fragrance-free formulas, for skin going through cancer treatment. Oily and blemish-prone skin is usually happier with lighter textures.
How it works
Both are mixtures of hydrocarbons refined from petroleum. Cosmetic and pharmaceutical grades are highly purified; the contamination concerns people read about relate to poorly refined, industrial grades. Petrolatum is one of the most effective ingredients for reducing water loss through the skin, and because it is inert it rarely irritates, which is why it is used on sensitive and post-procedure skin. It adds no nourishment of its own, so it works best over hydrating layers and alongside barrier lipids such as ceramides.
MG says
Valmont's Prime Regenera II, a rich balm whose formula opens with mineral oil and petrolatum, is what I love to use after a long-haul flight, in cold weather or when my skin feels particularly dry, stressed or sensitised. I often apply a thick layer as a mask and leave it to infuse for 20 minutes or so.
Cautions
Petrolatum and mineral oil rarely cause reactions, but their heavy texture can feel congesting on oily or blemish-prone skin, so keep them to dry areas or the evening if that's you. If you're having cancer treatment, check with your oncology team before introducing any new product.
