Ingredient review
Steareth-2
INCI: Steareth-2
A reliable emulsifier that helps create stable, creamy textures in skincare products with a low risk of irritation.
In plain English
Steareth-2 is a semi-synthetic ingredient made from stearyl alcohol (a fatty alcohol from plants or petroleum) and ethylene oxide. Its main job is to help oil and water mix together in creams and lotions, so the product stays smooth and doesn't separate. It's considered very gentle on skin and is commonly used in moisturizers and cleansers.
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-2 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-2.
- 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-2 is a polyethylene glycol (PEG) ether of stearyl alcohol. It belongs to the Steareth family of emulsifiers, where the number '2' indicates the average number of ethylene oxide units. It is a waxy solid at room temperature and is used to stabilize oil-in-water emulsions.
How it works
In a cosmetic formula, Steareth-2 sits at the boundary between oil and water droplets, reducing surface tension so they can mix into a stable emulsion. This prevents the product from separating into oily and watery layers, giving it a smooth, uniform texture that spreads easily on skin.
Pros
Gentle on skin
Steareth-2 has a very low irritation and comedogenic rating, making it safe for most skin types, including sensitive and acne-prone skin.
Improves product texture
It helps create smooth, creamy formulas that feel pleasant to apply and don't separate over time, so you get consistent performance from first use to last.
Cons and cautions
Potential trace impurities
As a PEG compound, Steareth-2 may contain trace amounts of 1,4-dioxane (a potential carcinogen) if not properly purified during manufacturing. Reputable brands ensure purification to safe levels.
Not natural
It is semi-synthetic, which may be a turn-off for consumers seeking 100% natural or organic skincare products.
Best for
- Anyone using creams or lotions who wants a stable, non-separating formula
- People with normal to dry skin who prefer rich but non-greasy textures
Use caution if
- Those who strictly avoid PEG compounds or semi-synthetic ingredients
Usage tips
Safety summary
Steareth-2 is considered safe for cosmetic use by major regulatory bodies. The main concern is potential contamination with 1,4-dioxane during manufacturing, but reputable suppliers and brands control this through purification and testing. Overall, it poses very low risk of skin irritation or clogged pores.
Research notes
The Cosmetic Ingredient Review (CIR) panel reviewed Steareth-2 and related compounds, concluding they are safe in current usage patterns. No significant human or animal studies indicate toxicity at cosmetic concentrations. Most evidence is based on formulation chemistry rather than clinical efficacy.
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 deemed Steareth-2 safe as used in rinse-off and leave-on products at concentrations up to 25%.
- Common uses
- Moisturizers, Creams, Lotions, Cleansers
- Environmental note
- Steareth-2 is not readily biodegradable, but it is not considered bioaccumulative. Its environmental impact is low at typical usage levels.
Good to know
- Steareth-2 is often paired with Steareth-21 (a more water-loving version) to fine-tune emulsion texture
- The number '2' refers to the average ethylene oxide chain length, which affects how oil- or water-loving the molecule is
Common questions
What is Steareth-2 in beauty products?
Steareth-2 is a semi-synthetic ingredient made from stearyl alcohol (a fatty alcohol from plants or petroleum) and ethylene oxide. Its main job is to help oil and water mix together in creams and lotions, so the product stays smooth and doesn't separate. It's considered very gentle on skin and is commonly used in moisturizers and cleansers.
What does Steareth-2 do in a beauty product?
In a cosmetic formula, Steareth-2 sits at the boundary between oil and water droplets, reducing surface tension so they can mix into a stable emulsion. This prevents the product from separating into oily and watery layers, giving it a smooth, uniform texture that spreads easily on skin.
Is Steareth-2 safe for most people?
Steareth-2 is considered safe for cosmetic use by major regulatory bodies. The main concern is potential contamination with 1,4-dioxane during manufacturing, but reputable suppliers and brands control this through purification and testing. Overall, it poses very low risk of skin irritation or clogged pores.
Who should be careful with Steareth-2?
Those who strictly avoid PEG compounds or semi-synthetic 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.