Ingredient review
Steareth-5
INCI: STEARETH-5
Steareth-5 is a gentle emulsifier that helps water and oil mix in your products, with a low risk of irritation or clogged pores.
In plain English
Steareth-5 is a synthetic ingredient made from stearyl alcohol (a fatty alcohol from plant or petroleum sources) and ethylene oxide. It acts like a bridge between water and oil, allowing them to blend into a stable cream or lotion. Because it's a mild surfactant, it also helps cleanse without stripping the skin. In simple terms, it's the ingredient that keeps your moisturizer smooth and prevents it from separating into watery and oily layers.
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
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Steareth-5 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-5.
- 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-5 is a polyethylene glycol (PEG) ether of stearyl alcohol, with an average of 5 ethylene oxide units. It belongs to the steareth family of emulsifiers, which are widely used in cosmetics to create stable emulsions.
How it works
Steareth-5 has both water-loving (hydrophilic) and oil-loving (lipophilic) parts. When added to a formula, it positions itself at the interface of oil and water droplets, reducing surface tension so they mix evenly. This creates a uniform, creamy texture that feels smooth on the skin and prevents separation over time.
Pros
Stable emulsions
Steareth-5 ensures your cream or lotion stays mixed and doesn't separate into oil and water layers, so you get a consistent product every time.
Low irritation potential
It is considered very mild on skin, making it suitable for sensitive skin types and daily use without causing redness or stinging.
Cons and cautions
Synthetic origin
Steareth-5 is made through a chemical process involving ethylene oxide, which may be a concern for those seeking fully natural or organic skincare.
Potential for trace impurities
During manufacturing, trace amounts of 1,4-dioxane (a possible contaminant) can form, though cosmetic-grade ingredients are purified to safe levels per regulations.
Best for
- Anyone using moisturizers, lotions, or creams who wants a stable, non-greasy texture
- People with normal to dry skin looking for gentle cleansing
Use caution if
- Those who strictly avoid PEG compounds or synthetic ethoxylated ingredients
Usage tips
Safety summary
Steareth-5 is considered safe for cosmetic use at typical concentrations. It has low skin irritation and sensitization potential. Regulatory bodies like the CIR and EU CosIng have reviewed it and found no significant safety concerns when used as intended. Trace impurities from manufacturing are controlled to safe limits.
Research notes
Studies on steareth compounds indicate they are mild surfactants with low acute toxicity. The CIR Expert Panel reviewed data on steareth-2 through steareth-100 and concluded they are safe in cosmetic formulations. No recent peer-reviewed studies specifically highlight Steareth-5 as a concern.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the US (FDA) and EU (CosIng) at concentrations up to 5% in leave-on products and higher in rinse-off products. The Cosmetic Ingredient Review (CIR) panel has deemed steareth compounds safe as used.
- Common uses
- Moisturizers, Cleansers, Conditioners, Hair styling products
- Environmental note
- Steareth-5 is biodegradable under standard conditions, but its production involves petrochemical-derived ethylene oxide, which has a moderate environmental footprint compared to plant-based alternatives.
Good to know
- Steareth-5 is part of a larger family of steareth emulsifiers (e.g., Steareth-2, Steareth-20) with varying water/oil balance.
- It is not a preservative, so products containing it still need a proper preservation system.
Common questions
What is Steareth-5 in beauty products?
Steareth-5 is a synthetic ingredient made from stearyl alcohol (a fatty alcohol from plant or petroleum sources) and ethylene oxide. It acts like a bridge between water and oil, allowing them to blend into a stable cream or lotion. Because it's a mild surfactant, it also helps cleanse without stripping the skin. In simple terms, it's the ingredient that keeps your moisturizer smooth and prevents it from separating into watery and oily layers.
What does Steareth-5 do in a beauty product?
Steareth-5 has both water-loving (hydrophilic) and oil-loving (lipophilic) parts. When added to a formula, it positions itself at the interface of oil and water droplets, reducing surface tension so they mix evenly. This creates a uniform, creamy texture that feels smooth on the skin and prevents separation over time.
Is Steareth-5 safe for most people?
Steareth-5 is considered safe for cosmetic use at typical concentrations. It has low skin irritation and sensitization potential. Regulatory bodies like the CIR and EU CosIng have reviewed it and found no significant safety concerns when used as intended. Trace impurities from manufacturing are controlled to safe limits.
Who should be careful with Steareth-5?
Those who strictly avoid PEG compounds or synthetic ethoxylated ingredients
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.