What Is Trideceth-3?
Trideceth-3 is a synthetic ingredient created by attaching a small chain of ethylene oxide units to isotridecanol, a fatty alcohol derived from petrochemical or plant sources such as coconut or palm oils. The resulting molecule is part oil and part water loving, which lets it mix liquids that normally separate. First introduced in personal care formulas during the late 20th century, it answered the industry’s need for gentle yet effective cleansers that would not leave a heavy residue. Production involves reacting isotridecanol with controlled amounts of ethylene oxide in a process called ethoxylation; the “3” in its name shows that three ethylene oxide units are added on average. You will most often find Trideceth-3 in face washes, micellar waters, makeup removers, exfoliating masks, lightweight lotions and some hair conditioners where a mild cleansing or blending action is required.
Trideceth-3’s Cosmetic Benefits/Uses
Formulators rely on Trideceth-3 for two main roles
- Cleansing: The ingredient lifts away dirt, excess oil and makeup by surrounding them so they can be rinsed off easily, helping products feel refreshing rather than stripping
- Emulsifying: It keeps water based and oil based components evenly mixed, giving creams and lotions a smooth stable texture that stays uniform on the shelf and spreads evenly on skin
Who Can Use Trideceth-3
Because it is a lightweight cleansing and emulsifying agent, Trideceth-3 usually works for normal, oily, combination and even dry skin that prefers gentle formulas. Most people with sensitive skin also tolerate it, though very reactive skin could feel a little tight if the finished product contains a high level of the ingredient or other strong surfactants.
The molecule itself is synthetic, and when the starting fatty alcohol is sourced from coconut or petrochemicals no animal input is involved. That makes Trideceth-3 generally suitable for vegans and vegetarians, but those who follow a strict lifestyle may want to check with the brand about the exact origin of the raw material.
No data link Trideceth-3 to risks during pregnancy or breastfeeding. It is considered a low concern ingredient by major regulatory bodies. Still, this is not medical advice, and anyone who is pregnant or nursing should run their skincare routine past a doctor to be on the safe side.
The ingredient does not make skin more sensitive to sunlight, so it is not regarded as photosensitising. It also plays well with most other cosmetic ingredients, which is why you will see it paired with acids, retinoids and fragrances without issues.
Potential Side Effects/Adverse Reactions
Responses to topically applied Trideceth-3 vary from person to person. The effects listed below are possibilities, not likely outcomes. When used at levels typical for cosmetics most users experience no problems.
- Mild skin irritation: Some people may notice short term redness or a stinging sensation, especially if their skin barrier is already compromised
- Dryness or tightness: In cleansers with higher surfactant loads the ingredient can remove too much natural oil leaving skin feeling dry
- Allergic contact dermatitis: Rare but possible an immune reaction that shows up as rash or itching
- Eye irritation: If a product accidentally enters the eyes it can cause watering or discomfort until rinsed out
If any of these effects occur stop using the product and seek advice from a qualified healthcare professional or pharmacist.
Comedogenic Rating
Rating: 1/5
Trideceth-3 is a lightweight surfactant that rinses away easily and does not leave a greasy film, so it is unlikely to block pores
Most acne-prone users can apply products containing this ingredient without added risk of breakouts
Keep in mind that the overall formula matters: if a product pairs Trideceth-3 with heavy oils or waxes the finished item could still feel clogging even though the ingredient itself is low on the scale
Summary
Trideceth-3 works as a gentle cleanser and an emulsifier. Its split structure lets it grab oil and dirt then mix them with water so they wash away, and it holds water and oil phases together in creams for a smooth feel
While not a headline act it is a reliable team player found in many everyday cleansers and light lotions around the world
Studies and regulatory reviews place Trideceth-3 in the low-risk category for skin irritation or health concerns at cosmetic levels, but trying a small patch first is still the safest way to see how your own skin responds