Common Name(s): Isostearyl isobutyrate,isostearyl alcohol (branched c18) isobutyric acid (branched c4) ester
DESCRIPTION
What It Does: Softens and conditions skin with a light, non-greasy feel.
Why It's Used: Used for its dual-branched ultra-light ester; both short acid and branched alcohol ensure minimal viscosity and fast spreading emollient properties; suitable for lightweight skin care where non-greasy texture is key.
How It Works: Ester of isostearyl alcohol (branched c18) (branched or specialty alcohol) with isobutyric acid (branched c4); branching reduces crystallinity and greasiness; provides smooth, dry-oil skin feel.
Typically Found In: Lightweight moisturizers,sunscreens,skin serums,body lotions
TECHNICAL DETAILS
Primary Category: Functional ingredient – emollient
Secondary Functions: Skin conditioning,texture modification,spreading agent
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 0.5%–10%
SOURCING & ETHICS
Vegan Status: Yes
Halal Status: Yes
Source Notes: Isostearyl alcohol (branched c18) and isobutyric acid (branched c4); plant or synthetic origin.
SKIN COMPATIBILITY
Irritancy Rating: 1/5 – very low
Comedogenicity Rating: 1/5 – low
Sensitivity Concerns: Generally well tolerated.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Good safety profile. ewg score: 1.
Works Well With: Other emollients,silicones,natural oils,humectants
Avoid Combining With: No significant incompatibilities
SCIENTIFIC NOTE
Isostearyl isobutyrate: branched c18 + branched c4 isobutyric acid; dual branching from both components creates an ultra-lightweight, fast-spreading emollient; very low viscosity despite c18 alcohol.
Last Verified: 2026-03-28
Primary Sources: Cosing database,inci dictionary