Common Name(s): Isobutyl isostearate,isobutanol (branched c4) isostearic acid (branched c18) 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 emollient; very fast spreading; non-greasy emollient properties; suitable for lightweight skin care where non-greasy texture is key.
How It Works: Ester of isobutanol (branched c4) (branched or specialty alcohol) with isostearic acid (branched c18); 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: Isobutanol (branched c4) and isostearic acid (branched c18); 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
Dual branching (isobutyl + isostearate) creates an ultra-lightweight, non-greasy emollient with fast spreading; suitable for high-spf sunscreens and lightweight skin care.
Last Verified: 2026-03-28
Primary Sources: Cosing database,inci dictionary