What Is Undecylenamidopropylamine Oxide?
Undecylenamidopropylamine Oxide is a specialty surfactant made from undecylenic acid, a fatty acid that can be obtained from castor oil. Chemically it is classified as an amine oxide, which means the molecule carries both water-loving and oil-loving parts, allowing it to mix oil and water. First developed in the late twentieth century as chemists searched for gentler cleansers than traditional soaps, it quickly found a place in personal care because it produced a rich lather without being too harsh on skin or hair.
The ingredient is produced through a few key steps. Undecylenic acid is first converted into an amide by reacting it with dimethylaminopropylamine. This amide is then oxidized with hydrogen peroxide to create the final amine oxide form. The result is a clear to pale yellow liquid that dissolves easily in water and works well over a wide pH range.
You will most often see Undecylenamidopropylamine Oxide in shampoos, body washes, bubble baths, facial cleansers, hand soaps, micellar waters and some makeup removers. Formulators also add it to cream cleansers, exfoliating scrubs and two-phase hair masks when they want extra foam and mildness.
Undecylenamidopropylamine Oxide’s Cosmetic Benefits/Uses
This multitasking surfactant brings several practical advantages to beauty formulas
- Cleansing: Its dual water-loving and oil-loving structure lifts away dirt, excess oil and product buildup without stripping skin or hair
- Hair Conditioning: Leaves a light, smooth feel on strands helping with detangling and reducing static, which is why it is popular in 2-in-1 shampoo-conditioner blends
- Foam Boosting: Enhances the volume, stability and creaminess of lather so products feel richer during use
- Hydrotrope: Helps keep other surfactants and oily ingredients dissolved in water-based formulas, preventing separation and improving clarity
Who Can Use Undecylenamidopropylamine Oxide
Because it is a mild surfactant most people can use products containing Undecylenamidopropylamine Oxide. Normal skin, dry skin, oily skin and sensitive skin usually tolerate it well, though anyone with a known allergy to amine oxides or to castor oil derivatives should avoid it. The ingredient is plant derived from castor oil so it is suitable for vegetarians and vegans. It is not known to interfere with pregnancy or breastfeeding when used topically but this is not medical advice and anyone who is pregnant or nursing should check with a physician before starting any new cosmetic product just to be safe. Undecylenamidopropylamine Oxide does not cause photosensitivity so there is no extra need for sun precautions beyond your usual SPF routine.
Potential Side Effects/Adverse Reactions
Responses to topical Undecylenamidopropylamine Oxide vary from person to person. The following list covers potential side effects that might occur, though they are uncommon when the ingredient is used at standard cosmetic levels.
- Mild skin irritation such as redness or itching if the formula is left on for a prolonged time
- Eye stinging or watering if the cleanser accidentally gets into the eyes
- Contact dermatitis in individuals with an existing sensitivity to amine oxides
- Dryness or rough feel on very porous hair if the product is overly concentrated
If you experience any discomfort stop using the product and consult a healthcare professional.
Comedogenic Rating
Rating: 0 / 5
Undecylenamidopropylamine Oxide is a water-soluble surfactant that rinses away cleanly and does not leave an oily film on the skin. It has a low molecular weight, is used at small levels, and is usually found in wash-off products like shampoos and cleansers, so it has virtually no chance of clogging pores. For these reasons it scores a solid 0.
That makes it suitable for people who are prone to acne or breakouts.
Because the ingredient is almost always rinsed off rather than left on the face, its already low pore-clogging risk is reduced even further.
Summary
Undecylenamidopropylamine Oxide acts as a gentle cleanser, light hair conditioner, foam booster and hydrotrope. Its dual water-loving and oil-loving structure lets it lift away grime while helping other ingredients stay blended, and the amine oxide head group leaves a smooth feel on skin and hair.
While it is not as famous as coco-betaine or sodium lauryl sulfate, it shows up in a fair number of mild shampoos, body washes and micellar waters because it creates rich foam without harshness.
Safety studies and real-world use show it is generally well tolerated with only rare irritation. Still, everyone’s skin is different so it is wise to patch test any new product that contains it before full use.