Ingredient review
Sodium/TEA-Undecylenoyl Carrageenan
INCI: SODIUM/TEA-UNDECYLENOYL CARRAGEENAN
A gentle, seaweed-based ingredient that forms a protective film on skin, helping to lock in moisture and shield against irritants.
In plain English
This ingredient is a modified version of carrageenan, a substance extracted from red seaweed. By attaching a fatty acid chain (undecylenic acid), it becomes better at spreading on the skin and forming a thin, invisible layer. This layer helps keep moisture from evaporating and can protect the skin from environmental stressors. It's often used in products for sensitive or dry skin because it's very mild and soothing.
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/TEA-Undecylenoyl Carrageenan 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/TEA-Undecylenoyl Carrageenan.
- 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 polymer created by chemically bonding undecylenic acid (a fatty acid) to carrageenan (a natural polysaccharide from red algae). The result is a water-soluble film former that feels smooth and non-sticky on the skin.
How it works
When applied, it dries down to form a flexible, breathable film on the skin's surface. This film reduces water loss (transepidermal water loss, or TEWL) and can help other ingredients stay on the skin longer. It also has a slight conditioning effect, making the skin feel soft and smooth.
Pros
Gentle film former
Creates a protective barrier that helps lock in moisture without clogging pores, making it suitable for sensitive and acne-prone skin.
Seaweed-derived
Sourced from red algae, it appeals to those seeking natural-origin ingredients in their skincare routine.
Cons and cautions
Potential tackiness
At higher concentrations, it can leave a slightly sticky or tacky residue on the skin, which may not be ideal for daytime wear under makeup.
Limited research
Compared to classic humectants like glycerin or hyaluronic acid, there is less published research on its long-term efficacy and safety.
Best for
- People with dry or dehydrated skin looking for extra moisture retention
- Those with sensitive skin who want a gentle, non-irritating protective layer
Use caution if
- Individuals who prefer lightweight, fast-absorbing products without any film feel
Usage tips
Safety summary
Sodium/TEA-Undecylenoyl Carrageenan is considered safe for topical 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 on this specific modified carrageenan is limited, but studies on carrageenan-based films show they can effectively reduce water loss and provide a soothing effect. The undecylenic acid component is known for its mild antimicrobial properties, though this is not a primary function in skincare formulations.
Common label clues
- Typical concentration
- 0.5% to 3%
- 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
- Serums, Moisturizers, Masks
- Environmental note
- Carrageenan is harvested from sustainably farmed red seaweed, which can have a lower environmental impact than land-based crops. However, the chemical modification process may involve synthetic reagents.
Good to know
- This ingredient is often found in products labeled as 'barrier repair' or 'moisture lock'.
- It is vegan-friendly and derived from seaweed, not animal sources.
Common questions
What is Sodium/TEA-Undecylenoyl Carrageenan in beauty products?
This ingredient is a modified version of carrageenan, a substance extracted from red seaweed. By attaching a fatty acid chain (undecylenic acid), it becomes better at spreading on the skin and forming a thin, invisible layer. This layer helps keep moisture from evaporating and can protect the skin from environmental stressors. It's often used in products for sensitive or dry skin because it's very mild and soothing.
What does Sodium/TEA-Undecylenoyl Carrageenan do in a beauty product?
When applied, it dries down to form a flexible, breathable film on the skin's surface. This film reduces water loss (transepidermal water loss, or TEWL) and can help other ingredients stay on the skin longer. It also has a slight conditioning effect, making the skin feel soft and smooth.
Is Sodium/TEA-Undecylenoyl Carrageenan safe for most people?
Sodium/TEA-Undecylenoyl Carrageenan is considered safe for topical 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 Sodium/TEA-Undecylenoyl Carrageenan?
Individuals who prefer lightweight, fast-absorbing products without any film feel
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.