Ingredient review
Sodium Isostareth-11 Carboxylate
INCI: Sodium Isostareth-11 Carboxylate
A gentle, low-irritation surfactant that effectively removes dirt and oil without stripping the skin.
In plain English
Sodium Isostareth-11 Carboxylate is a mild cleansing ingredient that helps lift away dirt, oil, and makeup from your skin. It belongs to a class of surfactants that are known for being less harsh than traditional sulfates, so they clean without leaving your skin feeling tight or dry. You'll often find it in gentle face washes and body cleansers designed for sensitive skin.
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
Sodium Isostareth-11 Carboxylate 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 Sodium Isostareth-11 Carboxylate.
- 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 isostearyl alcohol (a fatty alcohol) with ethylene oxide and then converting it to a carboxylate salt. It is part of the ether carboxylate family, known for mildness and good foaming properties.
How it works
In a cleanser, this molecule has a water-loving head and an oil-loving tail. When you lather it with water, the tails grab onto oils and dirt on your skin, while the heads stay in the water. Rinsing then washes away the trapped impurities, leaving skin clean without over-stripping its natural moisture barrier.
Pros
Mild on skin
This surfactant is much less irritating than sodium lauryl sulfate, making it a good choice for daily face washes and products for sensitive skin.
Good foam quality
It produces a rich, creamy lather that feels pleasant during cleansing, which can improve the user experience without harshness.
Cons and cautions
May not remove heavy makeup
If you wear long-wear or waterproof makeup, you might need a separate makeup remover or oil cleanser first, as this ingredient alone may not fully dissolve those products.
Potential for slight dryness
In very high concentrations or for extremely dry skin, it can still cause some tightness, though much less than harsher surfactants.
Best for
- People with normal to dry or sensitive skin looking for a gentle cleanser
- Those who prefer sulfate-free or low-irritation cleansing products
Use caution if
- Individuals with known allergies to polyethylene glycol (PEG) derivatives (rare)
Usage tips
Safety summary
Sodium Isostareth-11 Carboxylate is considered safe for use in cosmetics at typical concentrations. It has low skin irritation and sensitization potential, making it suitable for sensitive skin. No significant safety concerns have been raised by regulatory bodies.
Research notes
Ether carboxylates as a class are well-studied for mildness and low irritation. Specific studies on Sodium Isostareth-11 Carboxylate are limited, but its chemical relatives show good skin compatibility and biodegradability.
Common label clues
- Typical concentration
- 1–10% in rinse-off products; lower in leave-on formulations
- Regulatory status
- Approved for use in cosmetics in the EU, US, and other major markets. No specific restrictions beyond general cosmetic safety requirements.
- Common uses
- Facial cleansers, Body washes, Shampoos, Makeup removers
- Environmental note
- Semi-synthetic origin; generally considered biodegradable, but the ethylene oxide manufacturing process has environmental considerations.
Good to know
- This ingredient is often listed near the middle or end of an ingredient list, indicating moderate concentration.
- It is considered biodegradable and generally safe for aquatic environments at typical use levels.
Common questions
What is Sodium Isostareth-11 Carboxylate in beauty products?
Sodium Isostareth-11 Carboxylate is a mild cleansing ingredient that helps lift away dirt, oil, and makeup from your skin. It belongs to a class of surfactants that are known for being less harsh than traditional sulfates, so they clean without leaving your skin feeling tight or dry. You'll often find it in gentle face washes and body cleansers designed for sensitive skin.
What does Sodium Isostareth-11 Carboxylate do in a beauty product?
In a cleanser, this molecule has a water-loving head and an oil-loving tail. When you lather it with water, the tails grab onto oils and dirt on your skin, while the heads stay in the water. Rinsing then washes away the trapped impurities, leaving skin clean without over-stripping its natural moisture barrier.
Is Sodium Isostareth-11 Carboxylate safe for most people?
Sodium Isostareth-11 Carboxylate is considered safe for use in cosmetics at typical concentrations. It has low skin irritation and sensitization potential, making it suitable for sensitive skin. No significant safety concerns have been raised by regulatory bodies.
Who should be careful with Sodium Isostareth-11 Carboxylate?
Individuals with known allergies to polyethylene glycol (PEG) 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.