Ingredient review
Myreth-3
INCI: MYRETH-3
A gentle cleansing agent that helps products foam and rinse cleanly, with a low risk of irritation for most skin types.
In plain English
Myreth-3 is a mild surfactant, meaning it helps cleansers and shampoos foam up and remove dirt and oil without stripping your skin. It is made from myristyl alcohol (a fatty alcohol from coconut or palm oil) combined with a small amount of ethylene oxide. Because it is very gentle, it is often used in products for sensitive skin or in baby washes.
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
Myreth-3 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 Myreth-3.
- 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
Myreth-3 is a semi-synthetic surfactant and emulsifier. It belongs to the alkyl ether sulfate family and is created by reacting myristyl alcohol with 3 moles of ethylene oxide. It helps oil and water mix and improves the foaming and cleansing ability of rinse-off products.
How it works
In a cosmetic product, Myreth-3 reduces the surface tension between water and oil, allowing them to blend. This helps lift dirt, sebum, and makeup from the skin so they can be rinsed away. It also stabilizes emulsions, keeping creams and lotions from separating.
Pros
Very gentle on skin
Myreth-3 is one of the mildest surfactants, making it suitable for sensitive skin and daily use without causing tightness or irritation.
Good foam quality
It produces a rich, stable lather that feels pleasant and helps distribute the product evenly across the skin.
Cons and cautions
May be slightly drying for very dry skin
Although mild, repeated use in high concentrations can still strip natural oils from extremely dry or compromised skin.
Not natural or organic
Myreth-3 is semi-synthetic, so it may not fit a 'natural-only' skincare philosophy.
Best for
- People with normal to combination skin looking for a gentle cleanser
- Those who prefer mild, low-irritation surfactants in their daily routine
Use caution if
- Individuals with known allergies to ethoxylated ingredients (rare)
- Those strictly avoiding any synthetic processing
Usage tips
Safety summary
Myreth-3 is considered safe for use in cosmetics at typical concentrations. It has low skin irritation and sensitization potential. As with all ethoxylated ingredients, trace amounts of 1,4-dioxane may be present, but levels are tightly regulated and kept well below safety limits.
Research notes
Studies on alkyl ether sulfates, including Myreth-3, show they are mild surfactants with low acute toxicity and minimal skin irritation. The CIR panel has reviewed the broader class and deemed them safe for cosmetic use. No specific long-term human studies on Myreth-3 alone are available.
Common label clues
- Typical concentration
- Usually 1–5% in rinse-off products; lower in leave-on formulas
- Regulatory status
- Approved for use in cosmetics in the EU, US, and many other regions. The Cosmetic Ingredient Review (CIR) panel has reviewed alkyl ether sulfates and found them safe as used.
- Common uses
- Cleansers, Shampoos, Body washes, Emulsions
- Environmental note
- Myreth-3 is biodegradable, but its production involves ethylene oxide, which is derived from fossil fuels. Some manufacturers use sustainably sourced myristyl alcohol.
Good to know
- Myreth-3 is often listed alongside other 'myreth' surfactants (e.g., Myreth-4, Myreth-10) which have slightly different properties.
- It is considered biodegradable and safe for aquatic environments at typical use levels.
Common questions
What is Myreth-3 in beauty products?
Myreth-3 is a mild surfactant, meaning it helps cleansers and shampoos foam up and remove dirt and oil without stripping your skin. It is made from myristyl alcohol (a fatty alcohol from coconut or palm oil) combined with a small amount of ethylene oxide. Because it is very gentle, it is often used in products for sensitive skin or in baby washes.
What does Myreth-3 do in a beauty product?
In a cosmetic product, Myreth-3 reduces the surface tension between water and oil, allowing them to blend. This helps lift dirt, sebum, and makeup from the skin so they can be rinsed away. It also stabilizes emulsions, keeping creams and lotions from separating.
Is Myreth-3 safe for most people?
Myreth-3 is considered safe for use in cosmetics at typical concentrations. It has low skin irritation and sensitization potential. As with all ethoxylated ingredients, trace amounts of 1,4-dioxane may be present, but levels are tightly regulated and kept well below safety limits.
Who should be careful with Myreth-3?
Individuals with known allergies to ethoxylated ingredients (rare) Those strictly avoiding any synthetic processing
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.