Ingredient review
Capryleth-6 Carboxylic Acid
INCI: Capryleth-6 Carboxylic Acid
A gentle, low-irritation cleansing ingredient that effectively removes dirt and oil while being kind to sensitive skin.
In plain English
Capryleth-6 Carboxylic Acid is a mild cleansing ingredient that helps water and oil mix together so you can rinse away dirt, makeup, and excess oil without harsh scrubbing. It's often used in gentle face washes and micellar waters because it cleans without stripping your skin's natural moisture barrier.
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
Capryleth-6 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 Capryleth-6 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 made by reacting caprylic acid (a fatty acid from coconut or palm oil) with ethylene oxide, then modifying it to form a carboxylic acid group. It belongs to the class of alkyl ether carboxylic acids, known for their mildness.
How it works
It reduces the surface tension between water and oil, allowing oily impurities to be lifted from the skin and rinsed away. Its carboxylic acid group gives it a gentle, pH-balanced cleansing action that is less disruptive to the skin barrier compared to traditional soaps or sulfates.
Pros
Very gentle on skin
Unlike harsh sulfates, this ingredient cleans without stripping natural oils, making it ideal for sensitive or dry skin types.
Supports skin barrier health
Its mild, pH-friendly action helps maintain the skin's acid mantle, reducing the risk of irritation and transepidermal water loss.
Cons and cautions
Semi-synthetic production
It is derived from petrochemical ethylene oxide, which may be a concern for those seeking fully natural or plant-based ingredients.
Potential for mild dryness at high levels
In formulas with a high concentration of multiple surfactants, it could still contribute to slight dryness, especially for very dehydrated skin.
Best for
- People with dry, sensitive, or easily irritated skin looking for a gentle cleanser
- Anyone who prefers sulfate-free, mild cleansing formulas for daily use
Use caution if
- Those with known allergies to PEG compounds or ethylene oxide derivatives (rare)
Usage tips
Safety summary
Capryleth-6 Carboxylic Acid is considered safe for use in cosmetics at typical concentrations. It has low irritation and sensitization potential, making it suitable for sensitive skin. However, individuals with rare PEG allergies should exercise caution.
Research notes
Alkyl ether carboxylic acids like capryleth-6 carboxylic acid have been studied for their mildness and skin compatibility. Research indicates they are significantly less irritating than sodium lauryl sulfate and are well-tolerated in leave-on and rinse-off products. Most evidence comes from ingredient safety reviews and comparative surfactant studies.
Common label clues
- Typical concentration
- 1–10% in rinse-off products; lower in leave-on formulas
- Regulatory status
- Approved for use in cosmetics in the EU, US, and other major markets. No specific restrictions beyond general cosmetic safety regulations.
- Common uses
- Facial cleansers, Makeup removers, Micellar waters, Shampoos
- Environmental note
- As a semi-synthetic compound, its biodegradability is moderate. Some PEG derivatives have raised environmental concerns, but capryleth-6 carboxylic acid is generally considered safer than older ethoxylated surfactants.
Good to know
- Capryleth-6 Carboxylic Acid is often used in 'soap-free' cleansers and is considered a low-foaming surfactant.
- It is compatible with a wide pH range but performs best in slightly acidic formulas (pH 4.5–6.5).
Common questions
What is Capryleth-6 Carboxylic Acid in beauty products?
Capryleth-6 Carboxylic Acid is a mild cleansing ingredient that helps water and oil mix together so you can rinse away dirt, makeup, and excess oil without harsh scrubbing. It's often used in gentle face washes and micellar waters because it cleans without stripping your skin's natural moisture barrier.
What does Capryleth-6 Carboxylic Acid do in a beauty product?
It reduces the surface tension between water and oil, allowing oily impurities to be lifted from the skin and rinsed away. Its carboxylic acid group gives it a gentle, pH-balanced cleansing action that is less disruptive to the skin barrier compared to traditional soaps or sulfates.
Is Capryleth-6 Carboxylic Acid safe for most people?
Capryleth-6 Carboxylic Acid is considered safe for use in cosmetics at typical concentrations. It has low irritation and sensitization potential, making it suitable for sensitive skin. However, individuals with rare PEG allergies should exercise caution.
Who should be careful with Capryleth-6 Carboxylic Acid?
Those with known allergies to PEG compounds or ethylene oxide derivatives (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.