Beta-Sitosterol
Plant phytosterol structurally close to cholesterol. Softens skin and supports the lipid barrier, especially in dryness and flaking.
Evidence by route
Topical application
Small clinical studies show moderate anti-inflammatory and softening effects. No large standalone RCTs.
How to read tiers A–F
- CWeak evidence. In vitro data, open-label studies, or expert consensus
Tolerability and safety
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Safe
- Suitable for
- Oily, Dry, Sensitive, Combination, Normal
About this ingredient
Beta-Sitosterol is a natural plant phytosterol structurally close to cholesterol. Found in sunflower, rapeseed, avocado, nuts, and soybean oil. In pharmaceuticals it is an oral agent for lowering cholesterol and for benign prostatic hyperplasia; in cosmetics it is an emollient and anti-inflammatory ingredient. Mechanism. On skin it embeds into intercellular stratum corneum lipids, taking the functional niche of cholesterol, which – with ceramides and fatty acids – forms the three-component lipid matrix of the barrier. Maintaining the 1:1:1 lipid ratio (cholesterol:ceramides:fatty acids) reinforces the barrier in dry and atopic skin. Suppresses inflammatory signalling via NF-κB inhibition in vitro. Where applied. Creams and emollients for dry and atopic skin, post-retinoid and post-procedure products, hand and body balms, products for mature skin. Concentration 0.1–2%. In Spain part of Avène Cold Cream, La Roche-Posay Lipikar, Bioderma Atoderm. Evidence base. Direct topical RCTs on beta-sitosterol monotherapy are few. Most data come from phytosterol complexes or plant oils (soy, avocado) where it is one of the actives. Orally – Cochrane review Wilt 2002 showed symptom improvement in BPH, not relevant to cosmetics. Safety. CIR confirmed safety of phytosterols in cosmetics in 2013. Hypoallergenic, non-comedogenic, non-irritating. Allergy is rare, described as isolated cases with cross-reactivity to latex and soy. Pregnancy and lactation – safe topically. Used without restriction. Oral use (supplements) in pregnancy lacks adequate data – usually avoided. Particularly suitable for. Dry and atopic skin, scaling, impaired barrier (after retinoids, peels, laser), age-related dryness. Works well in ceramide formulas with cholesterol-to-ceramide-to-fatty-acid ratio 1:1:1, where sitosterol substitutes for cholesterol.
Frequently asked questions
Is Beta-Sitosterol safe during pregnancy?
Beta-Sitosterol is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Beta-Sitosterol for?
Beta-Sitosterol suits: oily, dry, sensitive, combination, normal.
What is Beta-Sitosterol and what does it do in cosmetics?
Plant phytosterol structurally close to cholesterol.
What's the INCI name for Beta-Sitosterol?
The INCI name is Beta-Sitosterol.
See Beta-Sitosterol in a product composition right on the store page
The Evigrade extension adds an evidence panel to iHerb, Sephora, Druni and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
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