What Is C11-15 Alketh-7 Carboxylic Acid?
C11-15 Alketh-7 Carboxylic Acid is a synthetic fatty acid made from medium-chain alcohols that contain 11 to 15 carbon atoms. These alcohols are first reacted with ethylene oxide to attach about seven repeating units of ethoxy groups, then they are oxidized so the molecule ends with a carboxylic acid group. The result is a mild, water-loving surfactant that mixes oil and water with ease.
The ingredient was introduced in the late 1970s as chemists searched for gentler alternatives to harsh soaps. By adjusting the length of the carbon chain and the number of ethoxy groups, they found a balance between cleansing power and skin friendliness. Over time it appeared in more personal care items because it proved reliable, affordable and easy to work with.
Today manufacturers make C11-15 Alketh-7 Carboxylic Acid in large reactors that control temperature and pressure so each step happens safely and cleanly. After purification the raw material is assessed for purity, pH and moisture content before it goes into finished formulas.
You will most often spot this ingredient in facial cleansers, micellar waters, body washes, exfoliating masks, makeup removers and light foaming shampoos. It may also pop up in wipes or pre-moistened pads where a gentle yet effective cleaning agent is needed.
C11-15 Alketh-7 Carboxylic Acid’s Cosmetic Benefits/Uses
Its value in cosmetics comes from one main role
Cleansing: The molecule lowers the surface tension of water so it can lift dirt, oil and makeup from skin or hair. Because it has both water-soluble and oil-soluble parts it forms tiny micelles that trap grime, allowing it to be rinsed away without stripping the natural lipids that keep the skin barrier comfortable.
Who Can Use C11-15 Alketh-7 Carboxylic Acid
This surfactant is generally considered friendly for all skin types including oily, combination, normal and even many sensitive skins because it cleans without an aggressive degreasing effect. Very dry or compromised skin might still prefer richer creamy cleansers that leave more lipids behind, but most users tolerate it well.
The compound is fully synthetic and contains no animal by-products, so it fits vegan and vegetarian lifestyles. Large manufacturers normally certify that neither animal-derived raw materials nor animal testing are involved in its production, though buyers should confirm a brand’s individual policy.
Pregnant or breastfeeding individuals are not known to face unique risks from topical use of this ingredient. It is regarded as low hazard in rinse-off and leave-on formulas, yet this is not medical advice and anyone expecting or nursing should review all skincare products with a healthcare professional for personal reassurance.
C11-15 Alketh-7 Carboxylic Acid does not cause photosensitivity, so sun exposure precautions specific to this ingredient are unnecessary. Users should still follow general sun safety practices recommended for daily skincare.
Potential Side Effects/Adverse Reactions
Reactions to topical C11-15 Alketh-7 Carboxylic Acid differ from person to person. The points below outline possible issues, but most people will not experience them when the ingredient is used at appropriate levels in a well-formulated product.
- Transient stinging or tingling, especially on very sensitive or broken skin
- Mild redness or irritation if the formula is too concentrated or left on the skin for extended periods
- Dryness or tightness when used in high-foam cleansers on already dehydrated skin
- Allergic contact dermatitis in rare cases of individual hypersensitivity
- Eye irritation if the product accidentally enters the eyes during use
If any unwanted reaction occurs stop using the product and seek advice from a qualified healthcare professional.
Comedogenic Rating
Rating: 1 (very low likelihood of clogging pores)
C11-15 Alketh-7 Carboxylic Acid is highly water soluble and typically used in rinse-off products, so it does not linger on skin long enough to block follicles. Its molecular structure is bulky and carries an acid group that makes it less prone to forming the waxy deposits often linked to breakouts. Formulators also use it at modest concentrations, further limiting any pore-clogging risk.
Because of this low rating it is generally suitable for people who are prone to acne or frequent breakouts.
Only in very rich leave-on formulas could residue become an issue, but such use is rare for this ingredient.
Summary
C11-15 Alketh-7 Carboxylic Acid is a synthetic fatty acid surfactant whose main job is cleansing. Its mix of oil-loving and water-loving parts forms micelles that surround dirt, oil and makeup so they rinse away without stripping the skin’s natural lipids. That balance between efficacy and mildness is why product developers reach for it in face washes, micellar waters, makeup removers and light shampoos.
While not the most famous surfactant on the market, it holds steady popularity in formulas that aim for gentle performance at a reasonable cost. Most safety assessments place it in the low-hazard category for both rinse-off and leave-on applications, and reported reactions are uncommon.
As with any cosmetic ingredient individual sensitivity can vary, so it is smart to patch test new products containing C11-15 Alketh-7 Carboxylic Acid before full use just to be safe.