Ingredient review
Steareth-6
INCI: Steareth-6
A gentle emulsifier that helps mix water and oil in creams and cleansers, with a low risk of irritation for most skin types.
In plain English
Steareth-6 is a mild cleansing and mixing ingredient made from stearyl alcohol (a fatty alcohol from plants or synthetic sources) that has been reacted with ethylene oxide. In simple terms, it helps water and oil blend together so your lotion or cleanser stays smooth and doesn't separate. It also helps remove dirt and oil from your skin without being harsh.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- semi synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Steareth-6 is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Steareth-6.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
Steareth-6 is a polyethylene glycol (PEG) ether of stearyl alcohol, meaning it's a semi-synthetic compound where stearyl alcohol is combined with about 6 units of ethylene oxide. This process makes the fatty alcohol water-friendly while keeping its oil-loving properties, allowing it to act as an emulsifier and mild surfactant.
How it works
In a cosmetic product, Steareth-6 sits at the boundary between water and oil droplets, reducing surface tension so they mix into a stable emulsion. As a surfactant, it also helps lift dirt and excess oil from the skin's surface, making it easier to rinse away with water. Its mildness comes from its large molecular structure, which is less penetrating and less likely to cause irritation.
Pros
Gentle emulsifier
Steareth-6 helps water and oil mix smoothly, so your cream or lotion stays consistent and doesn't separate. This means you get a uniform product every time you use it.
Mild cleansing action
It removes dirt and excess oil without being overly harsh, making it suitable for daily use in cleansers and shampoos without stripping your skin's natural moisture barrier.
Cons and cautions
Potential trace impurity
During manufacturing, Steareth-6 can be contaminated with 1,4-dioxane, a possible carcinogen. However, reputable brands use purification steps to keep levels well below safety limits set by regulators.
Not for extreme sensitivity
While generally mild, people with very sensitive or damaged skin might still experience mild irritation if the ingredient is present in high amounts, especially in leave-on products.
Best for
- People with normal to combination skin looking for a mild cleanser or lotion
- Those who prefer products with a creamy, non-greasy texture
Use caution if
- Individuals with known allergies to PEG compounds or ethylene oxide derivatives
Usage tips
Safety summary
Steareth-6 is considered safe for use in cosmetics at typical concentrations. The main safety concern is potential contamination with 1,4-dioxane, but this is tightly controlled by quality manufacturing. It has low irritation and comedogenic potential for most skin types.
Research notes
The Cosmetic Ingredient Review (CIR) panel has evaluated steareth compounds and concluded they are safe in cosmetic formulations when formulated to minimize 1,4-dioxane. No significant human or animal studies indicate toxicity at typical use levels.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics by the FDA and the European Commission. The Cosmetic Ingredient Review (CIR) panel has reviewed steareth compounds and found them safe as used, with the caveat that manufacturers should minimize 1,4-dioxane contamination.
- Common uses
- Cleansers, Lotions, Creams, Shampoos
- Environmental note
- Steareth-6 is semi-synthetic and not readily biodegradable in all environments. However, it is used in low concentrations and is generally considered low risk for aquatic ecosystems when rinsed down the drain.
Good to know
- Steareth-6 is part of a family of steareth compounds (e.g., Steareth-2, Steareth-20) where the number indicates how many ethylene oxide units are attached. Higher numbers mean more water solubility.
- It is often used alongside other emulsifiers to create a balanced, stable formula.
Common questions
What is Steareth-6 in beauty products?
Steareth-6 is a mild cleansing and mixing ingredient made from stearyl alcohol (a fatty alcohol from plants or synthetic sources) that has been reacted with ethylene oxide. In simple terms, it helps water and oil blend together so your lotion or cleanser stays smooth and doesn't separate. It also helps remove dirt and oil from your skin without being harsh.
What does Steareth-6 do in a beauty product?
In a cosmetic product, Steareth-6 sits at the boundary between water and oil droplets, reducing surface tension so they mix into a stable emulsion. As a surfactant, it also helps lift dirt and excess oil from the skin's surface, making it easier to rinse away with water. Its mildness comes from its large molecular structure, which is less penetrating and less likely to cause irritation.
Is Steareth-6 safe for most people?
Steareth-6 is considered safe for use in cosmetics at typical concentrations. The main safety concern is potential contamination with 1,4-dioxane, but this is tightly controlled by quality manufacturing. It has low irritation and comedogenic potential for most skin types.
Who should be careful with Steareth-6?
Individuals with known allergies to PEG compounds or ethylene oxide derivatives
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.