Peg-6 Stearate: 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 Stearate?

Peg-6 Stearate is a synthetic ingredient created by reacting stearic acid, a fatty acid most often derived from plant oils like coconut or palm, with polyethylene glycol. The result is a waxy, water-soluble compound that helps oil and water stay mixed. First introduced in the mid-20th century when chemists began exploring polyethylene glycol derivatives for personal care, it quickly earned a place in skincare and haircare labs thanks to its predictable performance and gentle feel on skin.

Manufacturing starts with purified stearic acid that is combined with ethylene oxide in a controlled process called ethoxylation. By limiting the reaction to an average of six ethylene oxide units, producers arrive at Peg-6 Stearate, a material with just the right balance of oil affinity and water compatibility. The finished product appears as off-white flakes or pellets that melt easily into cosmetic formulas.

You will find Peg-6 Stearate in many emulsions: daily moisturizers, lightweight lotions, cleansing milks, sheet mask serums, eye creams, sunscreens and even some styling creams. Its ability to blend oily actives with watery bases lets formulators create smooth textures without heavy waxes, making it popular in both rinse-off and leave-on products.

Peg-6 Stearate’s Cosmetic Benefits/Uses

In formulas Peg-6 Stearate serves one main purpose that delivers several practical benefits.

As an emulsifying agent it binds oil and water phases so the product remains uniform from the first squeeze to the last drop. This stability prevents separation, gives lotions a silky glide and helps active ingredients spread evenly across the skin. Because it is mild and non-greasy, it supports a lightweight feel that suits all skin types including those prone to sensitivity.

Who Can Use Peg-6 Stearate

Peg-6 Stearate is considered suitable for most skin types including dry, normal, combination and oily skin because it adds slip without heavy residue. Sensitive skin usually tolerates it well thanks to its mild profile, though anyone with a known polyethylene glycol allergy should steer clear.

The stearic acid used today is typically sourced from coconut or palm oil so finished Peg-6 Stearate is plant derived, making it appropriate for vegans and vegetarians. That said, shoppers may want to verify a brand’s sourcing policy to confirm no animal by-products were used.

Current cosmetic safety assessments find no reason pregnant or breastfeeding women cannot use products containing Peg-6 Stearate. Still, this is not medical advice and anyone who is expecting or nursing should run their routine by a healthcare professional just to be safe.

The ingredient does not trigger photosensitivity, meaning it will not make skin more prone to sunburn. It also plays well with other common skincare actives, so no special layering rules are required.

Potential Side Effects/Adverse Reactions

Reactions to topical Peg-6 Stearate vary from person to person. The points below outline potential side effects, though most users will not experience them when the ingredient is used correctly in a finished product.

  • Mild skin irritation – A small percentage of users may notice redness, stinging or itching on application
  • Allergic contact dermatitis – Very rare but possible in individuals sensitive to polyethylene glycol derivatives
  • Eye irritation – If a formula containing Peg-6 Stearate accidentally gets into the eyes it may cause temporary discomfort or watering
  • Enhanced penetration of other actives – Its emulsifying action can increase absorption of certain ingredients which could amplify their own irritation potential

If any of these effects occur stop using the product and consult a healthcare professional for personalized advice.

Comedogenic Rating

Rating: 1 out of 5

Peg-6 Stearate is primarily water soluble thanks to its polyethylene glycol portion, so it rinses off easily and does not linger on pores the way heavier stearic acid derivatives can. While the stearate tail brings a bit of oil affinity, its low concentration in finished products plus the hydrophilic PEG chain keeps the overall clogging potential minimal.

Because of this low score, the ingredient is generally considered suitable for people who are prone to acne or breakouts.

Keep in mind that the full formula matters. If Peg-6 Stearate is paired with highly occlusive oils or waxes, the overall product could still feel heavy on very oily skin.

Summary

Peg-6 Stearate is an emulsifier that lets oil and water stay blended, giving lotions and creams a consistently smooth texture. It works by positioning its fatty stearate end in the oil phase while its polyethylene glycol end prefers the water phase, creating a stable bridge between the two.

The ingredient is popular in mainstream skincare because it is reliable, easy to formulate with and provides a light non greasy finish that appeals to a broad range of consumers. It rarely steals the spotlight like trendy actives but quietly powers countless everyday moisturizers, cleansers and sunscreens.

Current safety reviews find Peg-6 Stearate to be low risk with only rare cases of irritation or allergy reported. As with any new cosmetic, it is wise to patch test a product that contains it before applying on larger areas, especially if you have sensitive or reactive skin.

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