emollients

Emollients are substances that soften and smooth the skin. They moisturize by forming a barrier that reduces water loss from the stratum corneum and by filling spaces between skin cells, resulting in a softer, more flexible surface. They are a key component of many topical products, including creams, lotions, and ointments, and are used to treat dry skin conditions such as xerosis and eczema.

Emollients comprise several classes. Occlusives such as petrolatum, mineral oil, lanolin, and silicones (dimethicone) form a physical barrier to reduce transepidermal water loss. Lipids and lipophilic esters such as isopropyl myristate, cetyl alcohol, shea butter, and plant oils act as lubricants and help restore the skin's lipid matrix. Humectants such as glycerin or propylene glycol attract water and may be included to increase hydration, often in combination with occlusives.

Mechanism and effects: by occluding the skin and by filling microgaps between corneocytes, emollients reduce water loss and improve elasticity. Some emollients can also aid in barrier repair by delivering fatty acids or ceramides.

Clinical use and safety: widely used for dry skin, dermatitis, and most routine skin care. They are generally well tolerated, but some individuals may experience irritation or allergic reactions to specific ingredients or fragrances. Occlusives can feel heavy or greasy and may worsen acne in some individuals; noncomedogenic options are available.