Ingredient review
Laureth-40
INCI: LAURETH-40
A mild cleansing and emulsifying agent, but can be drying or irritating for sensitive skin at higher concentrations.
In plain English
Laureth-40 is a synthetic ingredient that helps water and oil mix together in products like cleansers and shampoos. It also helps create a nice lather and remove dirt and oil from your skin. While it's generally considered safe, it can sometimes strip the skin of its natural moisture, especially if you have a sensitive or dry skin type.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Main practical flags: irritation is moderate; clogging risk is low.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- moderate
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Laureth-40 can be useful, but watch for some irritation potential.
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 Laureth-40.
- 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
moderateCan bother some users, especially with frequent use, damaged skin, or strong companion ingredients.
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
Laureth-40 is a polyethylene glycol (PEG) derivative of lauryl alcohol. It belongs to a family of surfactants known as ethers, which are created by adding ethylene oxide to fatty alcohols. The number '40' indicates the average number of ethylene oxide units, which makes it a relatively mild and water-soluble surfactant.
How it works
In a cosmetic product, Laureth-40 works by reducing the surface tension between water and oil. This allows the two to mix into a stable emulsion (like a lotion or cream) and helps water-based cleansers effectively lift and rinse away oily dirt, sebum, and makeup from the skin and hair.
Pros
Effective cleanser
Laureth-40 efficiently removes excess oil, dirt, and makeup, making it a reliable choice for daily cleansing routines.
Good emulsifier
It helps create stable, smooth lotions and creams by allowing water and oil to blend seamlessly, improving product texture and performance.
Cons and cautions
Potential for dryness
Because it can strip the skin of natural oils, regular use in high concentrations may lead to dryness, tightness, or irritation, especially for sensitive skin.
Synthetic origin
As a PEG-derived compound, it may be avoided by those seeking more natural or biodegradable ingredients, and some consumers have concerns about potential impurities from the manufacturing process.
Best for
- People with normal to oily skin types
- Those looking for effective cleansing in rinse-off products
Use caution if
- Individuals with very dry or compromised skin barriers
- Those who prefer completely natural or PEG-free formulations
Usage tips
Safety summary
Laureth-40 is considered safe for use in cosmetics at typical concentrations. However, like many surfactants, it can cause mild irritation or dryness in sensitive individuals, especially in leave-on products or high concentrations.
Research notes
Research on Laureth-40 is limited compared to more common surfactants. Available data suggests it is a mild cleansing agent with low acute toxicity. Its safety profile is supported by its long history of use in cosmetics and regulatory approvals.
Common label clues
- Typical concentration
- 1–5% in rinse-off products; lower in leave-on products
- Regulatory status
- Approved for use in cosmetics by the FDA and the European Commission, with concentration limits typically set by good manufacturing practices.
- Common uses
- Cleansers, Shampoos, Shower gels, Emulsions
- Environmental note
- As a synthetic surfactant, Laureth-40 may have moderate biodegradability. Some PEG compounds have raised concerns about aquatic toxicity, though specific data for Laureth-40 is limited.
Good to know
- The number '40' in Laureth-40 refers to the average number of ethylene oxide units, which influences its water solubility and mildness.
- It is often used in combination with other surfactants to balance cleansing power and gentleness.
Common questions
What is Laureth-40 in beauty products?
Laureth-40 is a synthetic ingredient that helps water and oil mix together in products like cleansers and shampoos. It also helps create a nice lather and remove dirt and oil from your skin. While it's generally considered safe, it can sometimes strip the skin of its natural moisture, especially if you have a sensitive or dry skin type.
What does Laureth-40 do in a beauty product?
In a cosmetic product, Laureth-40 works by reducing the surface tension between water and oil. This allows the two to mix into a stable emulsion (like a lotion or cream) and helps water-based cleansers effectively lift and rinse away oily dirt, sebum, and makeup from the skin and hair.
Is Laureth-40 safe for most people?
Laureth-40 is considered safe for use in cosmetics at typical concentrations. However, like many surfactants, it can cause mild irritation or dryness in sensitive individuals, especially in leave-on products or high concentrations.
Who should be careful with Laureth-40?
Individuals with very dry or compromised skin barriers Those who prefer completely natural or PEG-free formulations
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.