Peg-6 Isolauryl Thioether: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: July 1, 2025
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We verify all information on this page using publicly available nomenclature standards from The Personal Care Products Council (PCPC), the European Commission's CosIng database and documentation provided directly by ingredient manufacturers. Our analysis is based on technical data from these sources to ensure accuracy and reliability.

What Is Peg-6 Isolauryl Thioether?

Peg-6 Isolauryl Thioether is a synthetic ingredient made by attaching about six units of ethylene oxide to isolauryl alcohol, a fatty alcohol that is often sourced from coconut or palm kernel oil. A sulfur link, known as a thioether bond, connects the fatty part to the PEG (polyethylene glycol) chain, giving the molecule both oil-loving and water-loving parts. Chemists began experimenting with PEG-based surfactants in the mid-20th century to create gentler alternatives to soap. Over time they found that adding a thioether bridge improved the ingredient’s stability in formulas that include both water and oil. Today it appears in a variety of leave-on and rinse-off products such as facial cleansers, light lotions, creams, masks, sunscreens and hair conditioners.

Peg-6 Isolauryl Thioether’s Cosmetic Benefits/Uses

This ingredient is valued mainly for its work as an emulsifier, which means it helps water and oil blend into a smooth, even product that stays mixed over time. By keeping the formula uniform it improves the feel of a cream or lotion on the skin, prevents greasy spots and allows active ingredients to be spread more evenly for consistent results.

Who Can Use Peg-6 Isolauryl Thioether

Peg-6 Isolauryl Thioether is considered gentle enough for most skin types, including oily, combination, dry and even sensitive skin because it is used at low levels and does not leave a heavy film. People with known allergies to polyethylene glycols or sulfur-containing compounds should avoid it since they may be more prone to irritation. The ingredient is synthetically produced from plant-derived fatty alcohol and petro-based ethylene oxide, so it is generally accepted by vegans and vegetarians, though strict users may wish to confirm the plant origin of the fatty alcohol with the manufacturer.

Current safety data show no specific risks for women who are pregnant or breastfeeding when the ingredient is used in cosmetics. That said this is not medical advice and anyone who is pregnant or nursing should discuss all personal care products with a qualified healthcare provider to be extra safe.

Peg-6 Isolauryl Thioether does not make skin more sensitive to sunlight and there are no known interactions with common actives such as retinoids or exfoliating acids. It is also safe for all hair types if used in shampoos or conditioners.

Potential Side Effects/Adverse Reactions

Side effects or reactions to topical Peg-6 Isolauryl Thioether vary from person to person. The points below list potential issues only and are unlikely to occur for most users when the ingredient is properly formulated and used as directed.

  • Mild redness or stinging in individuals with very reactive skin, usually temporary
  • Contact dermatitis in people allergic to PEGs or thioether compounds
  • Eye irritation if a product containing the ingredient accidentally gets into the eyes
  • Enhanced penetration of other actives which could amplify the irritation potential of harsher ingredients used alongside it

If you experience any of these reactions discontinue use and consult a healthcare professional or dermatologist for guidance.

Comedogenic Rating

Rating: 1/5. Peg-6 Isolauryl Thioether is largely water soluble and used in small amounts so it seldom builds up inside pores. Its short fatty tail is balanced by a long PEG chain that rinses away with ease which keeps the pore-clogging potential low. For that reason it is generally considered fine for acne-prone or breakout-prone skin.

Its ability to disperse heavier oils evenly through a formula can also help stop those oils from pooling on the skin where they might otherwise clog pores.

Summary

Peg-6 Isolauryl Thioether is an emulsifier that keeps the watery and oily parts of a product blended which in turn makes lotions feel smoother cleansers rinse cleaner and active ingredients spread more evenly. It does this by parking its fatty end in the oil phase while its PEG side stays in the water phase essentially acting as a bridge between the two.

The name may not be famous but formulators turn to it for its reliability and gentle nature so you will spot it in a fair share of modern cleansers light creams sunscreens and hair conditioners.

Existing safety data points to a very low risk of irritation or long-term harm when used at normal cosmetic levels. Still it is smart to patch test any new product that contains this or any other unfamiliar ingredient just to be safe.

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