What Is Laureth-17 Carboxylic Acid?
Laureth-17 Carboxylic Acid is a synthetic ingredient made by linking ethylene oxide units to lauryl alcohol, then adding a carboxylic acid group to one end of the chain. The result is a molecule with both water-loving and oil-loving parts, which is why it works so well in cleansing formulas. Chemists began experimenting with ethoxylated fatty alcohols in the mid-20th century as gentler options to soap, and this particular member of the family found its place in cosmetics once formulators noticed its mildness on skin compared with earlier surfactants.
Production starts with plant-derived or petroleum-based lauryl alcohol. Ethylene oxide gas is reacted with the alcohol under controlled pressure and heat to attach about 16 units on average, creating Laureth-17. A final reaction introduces a carboxylic acid group, boosting water solubility and improving skin compatibility. The finished ingredient appears as a clear to slightly hazy liquid that dissolves easily in water.
You will usually see Laureth-17 Carboxylic Acid in facial cleansers, micellar waters, body washes, shampoos and makeup-removing wipes. Its mild nature also makes it popular in baby washes and low-foam cleansing lotions for sensitive or mature skin.
Laureth-17 Carboxylic Acid’s Cosmetic Benefits/Uses
This ingredient serves one main purpose in personal care formulas.
Cleansing: The dual nature of the molecule surrounds dirt, oil and makeup, lifts them from the skin or hair and allows them to be rinsed away with water. Because the ethoxylated chain softens its action, products containing Laureth-17 Carboxylic Acid tend to feel gentle, leave less tightness after washing and maintain the skin’s natural moisture balance.
Who Can Use Laureth-17 Carboxylic Acid
Thanks to its gentle cleansing action, Laureth-17 Carboxylic Acid suits most skin types including oily, dry, normal and combination. People with very sensitive or compromised skin can usually tolerate it, though anyone with a known surfactant allergy should proceed with care. The ingredient is synthesized from plant or petroleum sources and contains no animal-derived matter, so it is generally considered suitable for both vegetarians and vegans. Current research shows no specific concerns for women who are pregnant or breastfeeding when the ingredient is used in rinse-off or leave-on products at typical cosmetic levels, but this is not medical advice and expectant or nursing mothers should ask their doctor before adding any new skincare. Laureth-17 Carboxylic Acid does not make skin more prone to sunburn and has no known effect on photosensitivity.
Potential Side Effects/Adverse Reactions
Side effects from topical use of Laureth-17 Carboxylic Acid vary from person to person. The issues listed below are only potential outcomes and are unlikely for most users when the ingredient is formulated correctly.
- Mild skin irritation such as redness, itching or stinging
- Dry or tight feeling if the cleanser is left on the skin too long or used too often
- Eye irritation or watering if the product comes into direct contact with eyes
- Rare cases of allergic contact dermatitis in individuals sensitive to ethoxylated surfactants
- Increased penetration of other active ingredients that may themselves be irritating
If any unwanted reaction occurs stop use immediately and seek advice from a medical professional.
Comedogenic Rating
Rating: 1 / 5
Laureth-17 Carboxylic Acid is highly water soluble and formulated to lift oil and debris away from the skin then rinse off cleanly. Because it leaves little to no residue and its molecular size favors quick removal with water it has a very low likelihood of clogging pores. Trace amounts that may remain after rinsing are still rich in hydrophilic ethoxylate groups which further reduce any tendency to mix with sebum and form plugs.
For this reason the ingredient is generally considered suitable for people who are prone to acne or breakouts.
As with most surfactants the final formula matters. Heavy creams or balms that also contain rich plant oils could still feel occlusive even if Laureth-17 Carboxylic Acid itself is not. Rinse-off cleansers formulated with it are the lowest risk option.
Summary
Laureth-17 Carboxylic Acid is a mild cleansing agent that gently unhooks dirt oil and makeup from the skin without disturbing its natural moisture barrier. It does this through its split personality structure: a lauryl tail that grabs on to grime and a string of ethoxylate units plus a carboxylic acid head that keeps the whole complex suspended in water so it can be washed away.
While it is not as famous as household surfactants like sodium lauryl sulfate its reputation among formulators of sensitive skin products is solid and you will run into it in micellar waters baby washes and low-foam gels where a soft touch is the goal.
Current safety data shows a low risk profile when used at typical cosmetic levels. Still every skin is unique so it is wise to patch test any new product that features this ingredient to make sure it agrees with you.