Ingredient review
Myreth-3 Carboxylic Acid
INCI: MYRETH-3 CARBOXYLIC ACID
A gentle surfactant that cleans effectively without stripping the skin's natural moisture barrier, making it a good choice for sensitive skin.
In plain English
Myreth-3 Carboxylic Acid is a mild cleansing ingredient often used in soaps and shampoos. It helps lift away dirt and oil from your skin and hair without being harsh or drying. Think of it as a gentle cleaner that does its job without leaving your skin feeling tight or irritated.
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 Carboxylic Acid 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 Carboxylic Acid.
- 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 Carboxylic Acid is a semi-synthetic surfactant derived from myristic acid (a fatty acid found in coconut oil) and ethylene oxide. It belongs to the class of carboxylic acid surfactants, which are known for their mildness and ability to create a rich lather.
How it works
In a cosmetic product, Myreth-3 Carboxylic Acid works by reducing the surface tension between water and oil, allowing dirt and excess sebum to be rinsed away easily. Its mild nature means it doesn't strip the skin's natural oils as aggressively as some other surfactants, helping maintain the skin's moisture balance.
Pros
Mild on skin
Myreth-3 Carboxylic Acid is much gentler than traditional sulfates like SLS, making it ideal for daily use without causing irritation or dryness.
Supports moisture balance
Because it cleans without stripping natural oils, it helps keep your skin's moisture barrier intact, reducing the risk of tightness or flakiness after washing.
Cons and cautions
Limited heavy-duty cleansing
It may not be strong enough on its own to remove stubborn waterproof makeup or heavy sunscreen, so it's often paired with other surfactants in formulations.
Potential for mild sensitivity
While very rare, some people with extreme sensitivities might experience slight irritation, especially in leave-on products at higher concentrations.
Best for
- People with dry or sensitive skin looking for a gentle cleanser
- Anyone who prefers mild, non-stripping cleansing formulas
Use caution if
- Individuals with known allergies to coconut-derived ingredients (though rare)
Usage tips
Safety summary
Myreth-3 Carboxylic Acid is considered safe for use in cosmetics at typical concentrations. It has a low irritation and comedogenic risk, making it suitable for most skin types, including sensitive skin. No significant safety concerns have been reported in regulatory reviews.
Research notes
Research on Myreth-3 Carboxylic Acid is limited but consistent with its classification as a mild surfactant. Studies on similar carboxylic acid surfactants indicate low skin irritation potential and good biodegradability. Regulatory bodies like the Cosmetic Ingredient Review (CIR) have reviewed related compounds and found them safe for cosmetic use.
Common label clues
- Typical concentration
- 1% to 10% in rinse-off products; lower in leave-on formulas
- Regulatory status
- Approved for use in cosmetics in the EU, US, and many other regions. Generally recognized as safe when used as directed.
- Common uses
- Facial cleansers, Body washes, Shampoos, Micellar waters
- Environmental note
- Myreth-3 Carboxylic Acid is derived from renewable plant sources (coconut oil) and is biodegradable, making it a more sustainable choice compared to some petroleum-based surfactants.
Good to know
- This ingredient is often used in 'soap-free' or 'sulfate-free' cleansers to provide a gentle lather.
- It is considered biodegradable and environmentally friendlier than some harsher surfactants.
Common questions
What is Myreth-3 Carboxylic Acid in beauty products?
Myreth-3 Carboxylic Acid is a mild cleansing ingredient often used in soaps and shampoos. It helps lift away dirt and oil from your skin and hair without being harsh or drying. Think of it as a gentle cleaner that does its job without leaving your skin feeling tight or irritated.
What does Myreth-3 Carboxylic Acid do in a beauty product?
In a cosmetic product, Myreth-3 Carboxylic Acid works by reducing the surface tension between water and oil, allowing dirt and excess sebum to be rinsed away easily. Its mild nature means it doesn't strip the skin's natural oils as aggressively as some other surfactants, helping maintain the skin's moisture balance.
Is Myreth-3 Carboxylic Acid safe for most people?
Myreth-3 Carboxylic Acid is considered safe for use in cosmetics at typical concentrations. It has a low irritation and comedogenic risk, making it suitable for most skin types, including sensitive skin. No significant safety concerns have been reported in regulatory reviews.
Who should be careful with Myreth-3 Carboxylic Acid?
Individuals with known allergies to coconut-derived ingredients (though rare)
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.