Common Name(s): 22,23-dihydrostigmasterol,sitosterin
CAS Number: 83-46-5
DESCRIPTION
What It Does: Provides plant membrane sterol anti-inflammatory and barrier support with 5-alpha-reductase inhibition.
Why It's Used: Multi-function phytosterol combining barrier mimicry (identical to cholesterol structure) with anti-inflammatory and anti-androgenic activity for acne-prone and aging skin.
How It Works: Integrates into stratum corneum lipid bilayers analogous to cholesterol for barrier support. inhibits 5-alpha-reductase for dht reduction. inhibits nf-kb and cox for anti-inflammatory activity. cholesterol analog provides skin conditioning and membrane stabilization.
Typically Found In: Anti-inflammatory serums,anti-acne products,natural oils and butters (as unsaponifiable component)
TECHNICAL DETAILS
Primary Category: Active ingredient โ phytosterol anti-inflammatory
Secondary Functions: Barrier cholesterol analog,5-alpha-reductase inhibition
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 0.1%โ3%
SOURCING & ETHICS
Vegan Status: Conditional - supplier confirmation required
Halal Status: Unverified - supplier confirmation required
Source Notes: Plant-derived, synthetic or animal-derived. verify source. [audit 2026-07-29 rev2: the record's own source_notes does not assert a non-animal origin, or instructs the reader to verify with the supplier; "yes" asserts knowledge the record does not hold. determination requires shariah-panel sign-off.]
SKIN COMPATIBILITY
Irritancy Rating: 1/5 โ very low
Comedogenicity Rating: 1/5 โ low; formulation-dependent
Sensitivity Concerns: Non-irritating.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Excellent safety profile. ewg score: 1.
Works Well With: Humectants,ceramides,actives as carrier
Avoid Combining With: No significant incompatibilities
SCIENTIFIC NOTE
Beta-sitosterol's structural identity with cholesterol (only one additional ethyl group at c-24) allows it to substitute for cholesterol in cell membrane bilayers and skin barrier lipid structures. this structural mimicry explains its barrier-supportive activity while its c-24 ethyl group subtly alters enzyme interactions, providing 5-alpha-reductase inhibition not seen with mammalian cholesterol.
Last Verified: 2026-03-12
Primary Sources: Cosing database,bouic phytosterol review,cir safety assessment