Cholesterol

What it is

Cholesterol is not only a blood lipid: it is a structural component of every cell membrane and makes up roughly a quarter of the lipid mixture in the outermost layer of skin, alongside ceramides and free fatty acids. Epidermal cholesterol production falls with age, which is one reason older skin repairs its barrier more slowly. In cosmetics it is used both as a barrier lipid and as a co-emulsifier that helps build lamellar creams.

What it does well

• Completes the three-lipid mixture the barrier needs

  Foundational research showed that applying one or two of the three physiological lipids alone actually delays barrier recovery, and that only complete ceramide-cholesterol-fatty acid mixtures allow normal repair. A ceramide product without cholesterol and a fatty acid is working with one leg missing.

  Strong evidence

• Particularly relevant for older skin

  In aged mouse and human skin, a lipid mixture in which cholesterol was the dominant component significantly accelerated barrier recovery after tape stripping, while a fatty-acid-dominant mixture actually delayed it.

  Moderate evidence

Worth knowing

• Often confused with dietary or blood cholesterol

  Topical cholesterol has no bearing on blood cholesterol levels or cardiovascular risk; it is being used here as a structural skin lipid. This is a labelling misunderstanding rather than a safety issue.

  Matters most toAnyone who has seen cholesterol on an ingredient list and been alarmed by it.

• Frequently animal-derived

  Cosmetic cholesterol is commonly isolated from wool grease (lanolin), though plant-derived and fermentation-derived grades exist. The INCI name is the same either way, so vegan status has to come from the brand.

  Matters most toVegans, and people with a known lanolin allergy who prefer to avoid wool-derived materials.

Where the EU stands

Sources (2)

Every link goes to the original: a journal, a PubMed record or an EU document.

1. [1]
   Optimization of physiological lipid mixtures for barrier repair

   Journal of Investigative Dermatology · 1996 · doi:10.1111/1523-1747.ep12340135

   Only complete mixtures of ceramides, cholesterol and free fatty acids allow normal barrier recovery; making any one component up to threefold dominant accelerates repair further.

2. [2]
   Optimal ratios of topical stratum corneum lipids improve barrier recovery in chronologically aged skin

   Journal of the American Academy of Dermatology · 1997 · doi:10.1016/s0190-9622(97)70140-3

   In aged mouse and human skin, a cholesterol-dominant physiological lipid mixture significantly accelerated barrier recovery, whereas a fatty-acid-dominant mixture delayed it.