Ingredient review
Steareth-200
INCI: STEARETH-200
A synthetic thickener and emulsifier that helps stabilize formulas but may feel heavy on oily skin.
In plain English
Steareth-200 is a man-made ingredient derived from stearyl alcohol (a fatty alcohol from plant or petroleum sources) that has been reacted with 200 units of ethylene oxide. This makes it water-soluble and able to thicken and stabilize creams and lotions. It helps oil and water mix together so the product stays smooth and doesn't separate. Because it has a very large molecule, it stays mostly on the skin's surface and doesn't absorb deeply.
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-200 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-200.
- 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-200 is a high-mole ethoxylate of stearyl alcohol, meaning it has a long polyethylene glycol chain attached. It is a waxy solid at room temperature and is used primarily as a thickening agent and secondary emulsifier in cosmetic formulations.
How it works
In a cosmetic product, Steareth-200 helps increase viscosity (thickness) and stabilizes oil-in-water emulsions. Its large molecular size means it does not penetrate the skin easily, so it remains on the surface to provide a smooth, creamy texture and prevent the product from separating into oil and water layers.
Pros
Effective thickener
Provides a rich, creamy texture that improves the feel and stability of lotions and creams without needing many other thickeners.
Low irritation risk
Generally well-tolerated by most skin types, including sensitive skin, because it stays on the surface and doesn't penetrate deeply.
Cons and cautions
Potential heaviness
Can leave a greasy or heavy feel on oily or acne-prone skin, making it less suitable for lightweight or mattifying formulas.
Ethoxylation concerns
As an ethoxylated ingredient, trace amounts of 1,4-dioxane (a possible carcinogen) can form during manufacturing, though reputable brands purify to remove it.
Best for
- People with dry or normal skin who want rich, creamy textures
- Those looking for stable, non-separating lotions and creams
Use caution if
- Individuals with very oily or acne-prone skin who prefer lightweight, gel-based products
- Those seeking fully natural or plant-based ingredient lists
Usage tips
Safety summary
Steareth-200 is considered safe for use in cosmetics at typical concentrations. The main safety consideration is potential contamination with 1,4-dioxane from the ethoxylation process, but reputable suppliers purify the ingredient to very low levels. It has low skin irritation and sensitization potential.
Research notes
Research on Steareth-200 is limited, but it is generally regarded as safe based on its chemical class. The Cosmetic Ingredient Review (CIR) panel has reviewed similar ethoxylated alcohols and found them safe when formulated to minimize 1,4-dioxane. No specific studies on Steareth-200 absorption or toxicity are widely available.
Common label clues
- Typical concentration
- 0.5% to 5% in rinse-off products; lower in leave-on formulas
- Regulatory status
- Approved for use in cosmetics by the FDA and EU CosIng database. Manufacturers are expected to keep 1,4-dioxane levels below 10 ppm (often <1 ppm in purified grades).
- Common uses
- Creams, Lotions, Hair conditioners, Cleansers
- Environmental note
- Steareth-200 is not readily biodegradable due to its large molecular size, which can contribute to persistence in aquatic environments. However, it is used in low concentrations and is not considered a major environmental concern.
Good to know
- Steareth-200 is often used alongside Steareth-2 to create a balanced emulsifier pair.
- The number '200' refers to the average moles of ethylene oxide, making it one of the highest-mole ethoxylates used in cosmetics.
Common questions
What is Steareth-200 in beauty products?
Steareth-200 is a man-made ingredient derived from stearyl alcohol (a fatty alcohol from plant or petroleum sources) that has been reacted with 200 units of ethylene oxide. This makes it water-soluble and able to thicken and stabilize creams and lotions. It helps oil and water mix together so the product stays smooth and doesn't separate. Because it has a very large molecule, it stays mostly on the skin's surface and doesn't absorb deeply.
What does Steareth-200 do in a beauty product?
In a cosmetic product, Steareth-200 helps increase viscosity (thickness) and stabilizes oil-in-water emulsions. Its large molecular size means it does not penetrate the skin easily, so it remains on the surface to provide a smooth, creamy texture and prevent the product from separating into oil and water layers.
Is Steareth-200 safe for most people?
Steareth-200 is considered safe for use in cosmetics at typical concentrations. The main safety consideration is potential contamination with 1,4-dioxane from the ethoxylation process, but reputable suppliers purify the ingredient to very low levels. It has low skin irritation and sensitization potential.
Who should be careful with Steareth-200?
Individuals with very oily or acne-prone skin who prefer lightweight, gel-based products Those seeking fully natural or plant-based ingredient lists
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.