Cholesterol
Also known as: Cholest-5-en-3β-ol
Description
Cholesterol is an essential component of the stratum corneum lipid matrix, constituting approximately 25% of its total lipid content alongside ceramides (~50%) and free fatty acids (~25%). Together, these three lipid classes form the lamellar bilayers that create the skin's permeability barrier. Topical cholesterol is used in barrier repair formulations to restore the physiological lipid ratio disrupted in conditions such as atopic dermatitis, xerosis, and aged skin. It is particularly critical in elderly skin, where cholesterol synthesis declines disproportionately.
Mechanism of Action
Cholesterol integrates into the lamellar lipid bilayers of the stratum corneum, where it modulates the fluidity and organization of the intercellular lipid matrix. In the equimolar ratio with ceramides and free fatty acids, cholesterol enables the formation of the orthorhombic and liquid crystalline lipid phases necessary for optimal barrier function. It reduces transepidermal water loss (TEWL) by completing the lipid matrix. In cholesterol-deficient states (aging, atopic dermatitis), topical supplementation accelerates barrier recovery and normalizes lamellar body secretion.
Indications
- Impaired skin barrier
- Atopic dermatitis
- Xerosis / dry skin
- Aged skin barrier dysfunction
- Post-procedural barrier repair
- Adjunct to topical corticosteroid therapy
- Irritant contact dermatitis
Available Concentrations
Side Effects
- Non-irritating
- No known adverse effects at cosmetic concentrations
Contraindications
- Known hypersensitivity (extremely rare)
Pregnancy Category
Not classified (generally considered safe)