What Is Sodium/Tea-Undecylenoyl Carrageenan?
Sodium/Tea-Undecylenoyl Carrageenan is a modified form of carrageenan, a natural gummy substance extracted from red seaweed. Chemists take the long carbohydrate chains found in carrageenan and attach 10-undecenoic acid, a fatty acid obtained from castor or coconut sources. The resulting undecylenoyl derivatives are then neutralized with sodium ions and triethanolamine (TEA) to improve water dispersibility and skin feel. This hybrid of marine polysaccharide and plant-derived fatty acid offers the thickening power of carrageenan along with the conditioning traits of lipids.
Carrageenan itself entered the cosmetic world in the 1960s after decades of use as a food thickener. As formulators looked for cleaner-label alternatives to synthetic polymers they began experimenting with chemically tailored versions. The undecylenoyl modification was introduced to add surface affinity which helps the material bond to hair and skin. Production starts with seaweed harvesting, alkaline extraction of raw carrageenan, controlled reaction with 10-undecenoyl chloride or anhydride then careful pH adjustment using sodium hydroxide and TEA. The final powder or viscous liquid is easily rehydrated during manufacturing.
You will spot Sodium/Tea-Undecylenoyl Carrageenan in moisturizers, leave-on and rinse-off hair conditioners, styling gels, sheet masks, soothing after-sun lotions, anti-aging serums and lightweight daily sunscreens where it plays multiple roles that boost texture and performance.
Sodium/Tea-Undecylenoyl Carrageenan’s Cosmetic Benefits/Uses
This multifaceted ingredient helps products look better, feel smoother and stay stable over time.
- Emulsion stabilising: It thickens the water phase and forms a flexible network that keeps oil droplets evenly dispersed so creams stay uniform from the first pump to the last.
- Hair conditioning: The undecylenoyl portion deposits a breathable film on strands, reducing static and improving slip which makes detangling easier and leaves hair soft and manageable.
- Skin conditioning: On skin it forms a light, invisible layer that holds water at the surface delivering an immediate plumping effect while giving formulas a smooth, non-greasy finish.
Who Can Use Sodium/Tea-Undecylenoyl Carrageenan
Sodium/Tea-Undecylenoyl Carrageenan is considered friendly for most skin types. Its light film sits comfortably on dry, oily and combination skin without clogging pores or leaving a heavy residue. Sensitive skin generally tolerates it well thanks to its marine origin and mild chemistry, although people with a known seaweed allergy should proceed with caution.
The ingredient is entirely plant and algae derived so it aligns with vegan and vegetarian lifestyles. No animal by-products or animal testing are involved in its production process.
Current safety data show no specific risks for women who are pregnant or breastfeeding when the ingredient is used in rinse-off or leave-on cosmetics. This is not medical advice and anyone who is expecting or nursing should discuss all skincare choices with a qualified healthcare provider to be extra safe.
Sodium/Tea-Undecylenoyl Carrageenan does not make skin more sensitive to sunlight and can be worn during daytime without elevating the risk of sunburn. Its mild nature also means it can be paired with most actives such as retinoids or vitamin C without stability issues.
Potential Side Effects/Adverse Reactions
Reactions to topical Sodium/Tea-Undecylenoyl Carrageenan vary from person to person. The effects listed below are only potential outcomes and they are unlikely to affect the average user when the ingredient is formulated correctly.
- Mild redness or stinging in individuals with very reactive or compromised skin barriers
- Allergic contact dermatitis in people who are allergic to seaweed or iodine rich materials
- Scalp or hair buildup if high concentrations are used repeatedly without thorough cleansing
- Product separation when combined with highly cationic ingredients in DIY mixes which can lead to uneven application and irritation hotspots
If any irritation, itching or other discomfort develops stop using the product and seek medical advice if symptoms persist.
Comedogenic Rating
Rating: 1/5. Sodium/Tea-Undecylenoyl Carrageenan is a large, water-loving polysaccharide that sits on the skin surface rather than seeping into pores. The fatty undecylenoyl group adds light conditioning but is present at low levels and is partly neutralized, which keeps the overall texture non-greasy. Formulas using this ingredient usually contain high water content, further lowering any clogging risk.
Because of its low rating it is generally suitable for acne-prone or breakout-prone skin. Only very oily skin types using rich creams packed with other occlusives might notice congestion, but the ingredient itself is unlikely to be the culprit.
Its film-forming nature can trap heavy oils or impurities beneath if cleansing is inadequate, so thorough nightly cleansing is still recommended when using layered routines.
Summary
Sodium/Tea-Undecylenoyl Carrageenan thickens and stabilises emulsions, smooths and detangles hair, and forms a breathable moisture-holding film on skin. It does this by combining the gel-forming backbone of marine carrageenan with a small fatty tail that anchors to surfaces, giving products both structure and a silky finish.
The raw form of carrageenan is widespread in food but this tailored cosmetic version is still a niche pick, most common in eco-leaning skincare and lightweight conditioners that want natural feel without synthetic gums.
Current safety reviews show it to be low-toxicity, non-sensitising for most users and free of major regulatory limits. While reactions are rare, everyone’s skin is unique so it is wise to patch test any new product containing the ingredient to ensure personal compatibility.