PEG-4 PROLINE LINOLEATE

What Is PEG-4 PROLINE LINOLEATE?

An ester formed between PEG-4, the amino acid proline, and linoleic acid (an essential omega-6 fatty acid). This multi-functional ingredient combines the skin-conditioning properties of proline (a key component of collagen) with the barrier-repair benefits of linoleic acid, made water-dispersible by the PEG chain. It helps strengthen the skin barrier, improve moisture retention, and provides anti-aging benefits.

Key Skin Benefits

• + Supports skin barrier function — linoleic acid is essential for ceramide synthesis and barrier integrity
• + Collagen support — proline is a major amino acid in collagen structure
• + Improves skin hydration — helps reduce trans-epidermal water loss (TEWL)
• + Anti-aging potential — combines barrier repair with structural protein support

Pros

• + Multi-functional — combines amino acid, essential fatty acid, and conditioning benefits
• + Linoleic acid benefits well-documented — PMID: extensive research on barrier repair in atopic skin
• + CIR-reviewed — PEG esters considered safe in cosmetics
• + Non-comedogenic — suitable for facial use
• + Mild — well-tolerated on sensitive and compromised skin

Cons

• − PEG content — ethoxylated ingredient with trace contaminant risk
• − Limited specific clinical data on this exact ester — most evidence from individual components
• − Semi-synthetic — not fully natural

Specifications

Safety Ratings

Regional Regulatory Limits

Typical Usage % by Product Type

References

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