A non-ionic emulsifier and co-surfactant. It stabilizes the formula and helps blend phases. Well tolerated.
Topical application
BLimited evidence. One RCT or several controlled studies with limitations.
A functional emulsifier. Safe.
Trideceth-9 is a non-ionic emulsifier that also acts as a co-surfactant. Its INCI name is Trideceth-9. In a formula it helps bind the oil and water phases, stabilizes the blend, and improves the solubilization of other ingredients. This is a functional ingredient, not a skincare active. It does not treat the skin; it gives the formula structure and stability. In that role it does its job well and is used to keep the product uniform. Applied topically it has no systemic relevance, so it can be used during pregnancy and breastfeeding. As a surfactant it is mild. Its irritation and allergy potential is low and it suits sensitive skin. By its surfactant nature it could dry slightly at high concentrations, but at usual levels it tolerates well and most people see no reaction.
Irritation potential
LowAllergen risk
LowPregnancy
SafeSuitable for
The Evigrade extension adds an evidence panel to iHerb, Sephora, Druni and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
Trideceth-9 is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
Trideceth-9 suits: normal, dry, combination, oily, sensitive.
A non-ionic emulsifier and co-surfactant.
The INCI name is Trideceth-9. It may also appear as: Тридецет-9.
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