PEG-4 PROLINE LINOLENATE

INCI: PEG-4 PROLINE LINOLENATE | Function: Skin Conditioning, Emollient | Type: Moisturizer

What Is PEG-4 PROLINE LINOLENATE?

A PEG-4 ester of proline and linolenic acid (alpha-linolenic acid, an omega-3 essential fatty acid). Similar to its linoleate counterpart but with the omega-3 fatty acid, this ingredient provides skin-conditioning, barrier-supporting, and anti-inflammatory benefits. Linolenic acid is known for its soothing properties and ability to calm irritated, inflamed skin.

Key Skin Benefits

+ Omega-3 fatty acid benefits — linolenic acid has anti-inflammatory and skin-soothing properties
+ Barrier support — essential fatty acids are critical for healthy stratum corneum function
+ Collagen-amino acid component — proline supports skin structural proteins
+ Calms irritated skin — omega-3 fatty acids help reduce redness and sensitivity

Pros

+ Anti-inflammatory properties of omega-3 supported by extensive PubMed research
+ Multi-functional — combines soothing, barrier repair, and conditioning
+ CIR-reviewed — safe for cosmetic use
+ Non-comedogenic
+ Suitable for sensitive and reactive skin types

Cons

− PEG content — ethoxylation contaminant concerns
− Limited specific clinical data on this exact compound
− Fatty acid esters may oxidize over time — requires proper preservation and packaging

Specifications

Property	Value
Usage Areas	Face, Eye, Body
Product Type	Leave-On, Rinse-Off
Source	Semi-synthetic
Natural Level	Semi-synthetic

Safety Ratings

Metric	Rating
Skin Sensitivity	1/5 (very low)
Comedogenic Rating	0/5
EWG Score	1/10

Regional Regulatory Limits

Region	Leave-on %	Rinse-off %	Status
EU (CosIng)	No limit	No limit	Allowed
US (CIR/FDA)	No limit	No limit	Allowed
Japan (MHLW)	No limit	No limit	Allowed
ASEAN	No limit	No limit	Allowed
China (NMPA)	No limit	No limit	Allowed

Typical Usage % by Product Type

Product Type	Typical %
Soothing creams	0.5-3%
Barrier serums	0.5-2%
Sensitive skin moisturizers	0.5-2%

References

CIR (2018) — Safety Assessment of Amino Acid-Derived Cosmetic Ingredients.
Choi FD et al. (2019) — Oral Collagen Supplementation: A Systematic Review of Dermatological Applications. J Drugs Dermatol. PMID: 30681787.
CosIng (2025) — European Commission Cosmetic Ingredient Database. https://ec.europa.eu/growth/tools-databases/cosing/
EWG Skin Deep — Cosmetic Ingredient Database. https://www.ewg.org/skindeep/
Lin TK et al. (2018) — Essential fatty acids and skin barrier. Int J Mol Sci. PMID: 29280987.

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