What Is C11-15 Alketh-3?
C11-15 Alketh-3 is a synthetic ingredient made by reacting a blend of C11 to C15 fatty alcohols with about three units of ethylene oxide. This reaction links the fatty alcohols to polyethylene glycol creating a water-loving end and an oil-loving end in the same molecule. Because both portions coexist, the finished compound can pull oil and water together, a trait highly valued in personal care formulas.
The fatty alcohol backbone is typically produced from petroleum-derived feedstocks or plant oils that are refined and broken down into the desired carbon chain lengths. Manufacturers then guide the ethoxylation step under controlled heat and pressure, after which the mixture is purified to cosmetic-grade standards.
Similar ethoxylated fatty alcohols first appeared in the mid-20th century when formulators searched for more stable and versatile emulsifiers. Over time, C11-15 Alketh-3 gained popularity because its moderate chain length balances effectiveness with a light skin feel.
You will most often see this ingredient in facial moisturizers, cleansing milks, sunscreens, lightweight serums, body lotions, hair conditioners and rinse-off masks where it helps keep the formula uniform from the first squeeze to the last drop.
C11-15 Alketh-3’s Cosmetic Benefits/Uses
In skincare and haircare, C11-15 Alketh-3 serves one key purpose that supports both product stability and user experience.
- Emulsifying agent: It binds oil and water phases so creams, lotions and liquids stay smooth, preventing separation during storage or use. A well-formed emulsion spreads evenly, delivers active ingredients reliably and feels pleasant without greasy residue.
Who Can Use C11-15 Alketh-3
C11-15 Alketh-3 is generally well tolerated by most skin types thanks to its lightweight feel and low residue. Normal, dry and oily skin usually handle it without issue while those with very sensitive or compromised skin should keep an eye out for any tingling or redness since any emulsifier can occasionally disrupt a fragile barrier.
The ingredient is produced from synthetic or plant-derived fatty alcohols and ethylene oxide, not animal-sourced materials, so it is considered suitable for both vegetarians and vegans. As always, the finished product’s overall formulation and brand policies matter if cruelty free status is a priority.
No data suggest that C11-15 Alketh-3 poses special risks for women who are pregnant or breastfeeding when used in rinse-off or leave-on cosmetics. This is not medical advice and anyone who is pregnant or nursing should discuss all skincare choices with a qualified health professional for extra reassurance.
C11-15 Alketh-3 does not increase sun sensitivity and can be used day or night without altering your usual SPF habits. It is compatible with most common skincare actives and does not interfere with makeup wear or hair-styling products.
Potential Side Effects/Adverse Reactions
Responses to topical C11-15 Alketh-3 vary from person to person. The points below cover potential side effects yet these outcomes are uncommon when the ingredient is correctly formulated and used as intended.
- Mild skin irritation: transient stinging or redness can occur, especially on very sensitive or broken skin
- Contact dermatitis: rare allergic reactions may lead to itching, rash or swelling
- Dryness or tightness: over-use in high concentrations could strip natural oils leaving skin feeling dry
- Eye irritation: if the product accidentally gets into the eyes it may cause watering or discomfort until thoroughly rinsed
If any of these reactions develop stop using the product and seek guidance from a medical professional or pharmacist.
Comedogenic Rating
Rating: 1 / 5
C11-15 Alketh-3 is mostly made of lightweight synthetic fatty alcohols joined to small polyethylene glycol chains. The hydrophilic PEG portion keeps the molecule water friendly so it rinses or spreads without forming an occlusive film that could trap oil and debris in pores. While any fatty alcohol derivative can add a hint of richness, its short ethoxylated structure means it is far less likely than heavier waxes or butters to block follicles. For most users this places it near the low end of the comedogenic scale.
Because of this low rating it is generally acceptable for people who are prone to acne or breakouts, especially when used in well balanced formulas at typical usage levels.
As with all emulsifiers the overall comedogenic potential depends on the full recipe. A product that pairs C11-15 Alketh-3 with highly occlusive oils could still trigger congestion, whereas a lightweight moisturizer or cleanser will not.
Summary
C11-15 Alketh-3 is an emulsifier that lets water and oil coexist in a smooth stable blend. Its split personality structure, with an oily tail gripping lipids and a water loving head that mingles with the aqueous phase, prevents separation so creams stay uniform, feel light and deliver actives evenly.
The ingredient enjoys solid but quiet popularity. It is not a marketing buzzword yet formulators value its reliability and silky feel, so it shows up in many everyday lotions cleansers and sunscreens without fanfare.
Overall safety data are favorable. Reports of irritation or allergy are rare and it earns a low comedogenic score. Still, every skin is different so it is wise to patch test a new product that contains C11-15 Alketh-3 before adding it to a full routine.