Ingredient review
Undeceth-5 Carboxylic Acid
INCI: UNDECETH-5 CARBOXYLIC ACID
A gentle, coconut-derived surfactant that cleanses without stripping the skin, making it ideal for sensitive or dry skin types.
In plain English
Undeceth-5 Carboxylic Acid is a mild cleansing ingredient made from coconut oil. It helps remove dirt, oil, and makeup without being harsh or drying. Think of it as a gentle soap that cleans 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
Undeceth-5 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 Undeceth-5 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
A semi-synthetic surfactant (cleansing agent) produced by reacting undecyl alcohol (from coconut oil) with ethylene oxide and then adding a carboxylic acid group. This structure gives it both water-loving and oil-loving properties, allowing it to lift away impurities.
How it works
It works by reducing the surface tension between water and oil, allowing them to mix. This helps water rinse away sebum, makeup, and dirt. Its mildness comes from its large, gentle molecular structure, which is less likely to penetrate and irritate the skin barrier.
Pros
Very gentle on skin
Its large molecular structure means it cleans without penetrating the skin barrier, reducing the risk of irritation and dryness.
Coconut-derived and biodegradable
Sourced from renewable coconut oil, it is considered more environmentally friendly than many petroleum-based surfactants.
Cons and cautions
Limited cleansing power
It may not effectively remove heavy makeup or waterproof sunscreen on its own, often requiring a double-cleanse routine.
Potential for slight drying
In high concentrations or without balancing ingredients, it can still leave skin feeling a bit tight, though much less than harsher surfactants.
Best for
- People with dry or sensitive skin looking for a non-stripping cleanser
- Those who prefer mild, coconut-derived surfactants over sulfates
Use caution if
- Individuals who need a deep-cleansing formula for heavy makeup or waterproof products
Usage tips
Safety summary
Undeceth-5 Carboxylic Acid is considered safe for use in cosmetics at typical concentrations. It has a low irritation and comedogenic risk, making it suitable for sensitive skin. No significant safety concerns have been reported in regulatory reviews.
Research notes
Research indicates that ether carboxylic acids like Undeceth-5 Carboxylic Acid are mild surfactants with good skin compatibility. Studies show they cause less protein denaturation and skin barrier disruption compared to sodium lauryl sulfate. However, most evidence comes from ingredient-level safety assessments rather than large-scale human trials.
Common label clues
- Typical concentration
- 1–10% in rinse-off products; lower in leave-on products
- Regulatory status
- Approved for use in cosmetics in the EU, US, and other major markets. Generally recognized as safe when used as directed.
- Common uses
- Facial cleansers, Body washes, Shampoos, Makeup removers
- Environmental note
- Derived from coconut oil, a renewable resource. It is biodegradable and considered less harmful to aquatic life than some traditional surfactants.
Good to know
- Often listed as 'PEG-5 Undecyl Ether Carboxylic Acid' on labels.
- Commonly used in combination with other mild surfactants to boost foam and cleaning ability.
Common questions
What is Undeceth-5 Carboxylic Acid in beauty products?
Undeceth-5 Carboxylic Acid is a mild cleansing ingredient made from coconut oil. It helps remove dirt, oil, and makeup without being harsh or drying. Think of it as a gentle soap that cleans without leaving your skin feeling tight or irritated.
What does Undeceth-5 Carboxylic Acid do in a beauty product?
It works by reducing the surface tension between water and oil, allowing them to mix. This helps water rinse away sebum, makeup, and dirt. Its mildness comes from its large, gentle molecular structure, which is less likely to penetrate and irritate the skin barrier.
Is Undeceth-5 Carboxylic Acid safe for most people?
Undeceth-5 Carboxylic Acid is considered safe for use in cosmetics at typical concentrations. It has a low irritation and comedogenic risk, making it suitable for sensitive skin. No significant safety concerns have been reported in regulatory reviews.
Who should be careful with Undeceth-5 Carboxylic Acid?
Individuals who need a deep-cleansing formula for heavy makeup or waterproof products
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.