Emulsifier

Trideceth-15

INCI: TRIDECETH-15

Reviewed by Daisy · Last updated 14 Aug 2026

A mild surfactant that helps oils and water mix smoothly in formulations

Best For Skin Types

All

What Is Trideceth-15?

Trideceth-15 is a synthetic surfactant derived from tridecyl alcohol. It belongs to a class of ingredients called ethoxylates, which are created by combining a fatty alcohol with ethylene oxide. In skincare, it functions primarily as an emulsifier—a substance that allows water-soluble and oil-soluble ingredients to blend together rather than separate.

This ingredient is used sparingly in skincare products (found in approximately 0.1% of formulations) and serves a technical role rather than a direct skin-benefit role. It helps create stable, homogeneous textures in creams, serums, and other emulsified products.

How It Works

Trideceth-15 works through its chemical structure, which contains both water-loving (hydrophilic) and oil-loving (lipophilic) regions. This dual nature allows it to sit at the interface between oil and water phases, preventing them from separating and creating an even emulsion.

Rather than providing direct benefits to skin cells, it enables the creation of formulations where other actives can work effectively. It is used in very small concentrations, where its primary function is technical rather than therapeutic.

Clinical Evidence & References

Research on trideceth-15 specifically in skincare is limited. The broader literature on skin ageing, barrier function, and immune defence emphasises the importance of well-formulated, stable products that can deliver active ingredients effectively—an area where emulsifiers like this play a supporting role.

There is no evidence that trideceth-15 directly improves skin health or addresses skin concerns. Its value lies in enabling formulators to create stable, reliable products that keep other beneficial ingredients properly suspended and deliverable to the skin.

How to Use

Trideceth-15 requires no specific usage guidance as it is not an active ingredient. Simply use the product containing it as directed. Its presence is entirely about ensuring the formula itself remains stable and performs as intended.

Safety & Precautions

Trideceth-15 is generally well-tolerated and considered safe for use in cosmetics. It is not a known irritant or sensitiser at typical concentrations used in skincare formulations.

Frequently Asked Questions

From the Clinic

Not sure what your skin actually needs?

Two minutes, a few questions, and we’ll point you at what matters — no guesswork.

Take the skin quiz

Learn More About Skincare Ingredients

Explore our comprehensive ingredient glossary to understand what's in your products.

Browse All Ingredients

Authorised Stockist

Official UK retailer

Tracked Delivery

Free UK shipping over £50

5 Star Rating

Trusted by thousands

Expert Advice

Free consultations