What Is C11-15 Alketh-7?
C11-15 Alketh-7 is a synthetic ingredient made by reacting a blend of C11 to C15 fatty alcohols with about seven units of ethylene oxide. The result is a polyethylene glycol ether that behaves like a mild surfactant. The fatty alcohols used are usually produced from petroleum or plant oils, while the ethoxylation step takes place in controlled factory settings to ensure purity and consistency.
The cosmetic industry began turning to ethoxylated fatty alcohols in the 1970s when formulators needed reliable emulsifiers that stayed stable over a wide pH range. C11-15 Alketh-7 quickly found favor because it balances oil and water without feeling heavy or greasy.
Manufacturing starts with the selection of mid-chain fatty alcohols, which are purified then reacted with ethylene oxide gas under pressure. The number “7” in the name tells chemists how many ethylene oxide units are added on average. After reaction, the mixture is filtered, tested for residual impurities then cooled into a clear to pale yellow liquid.
You will most often spot C11-15 Alketh-7 in lightweight moisturizers, face masks, sunscreens, body lotions, makeup removers and leave-on hair conditioners. It is also common in anti-aging serums where a stable oil-in-water base is needed to keep active ingredients evenly dispersed.
C11-15 Alketh-7’s Cosmetic Benefits/Uses
This ingredient serves a single yet important role in formulations.
Emulsifying: C11-15 Alketh-7 binds together water and oil so a product stays smooth and uniform from the first pump to the last. By holding the mixture in place it prevents separation, improves spreadability and helps active ingredients deliver evenly across the skin or hair.
Who Can Use C11-15 Alketh-7
C11-15 Alketh-7 is generally considered suitable for all skin types including oily, normal, combination and dry skin because it stays lightweight and does not leave an occlusive film. Most sensitive skin users also tolerate it, though anyone with a known sensitivity to ethoxylated ingredients should approach with caution.
The ingredient is synthesized from petroleum or plant-derived fatty alcohols and contains no animal by-products. For that reason products using C11-15 Alketh-7 are usually appropriate for vegans and vegetarians unless the rest of the formula contains animal ingredients.
No data suggest that this emulsifier poses a specific risk to pregnant or breastfeeding women when used topically at cosmetic levels. This is not medical advice and anyone who is pregnant or nursing should have their healthcare provider review any skincare they plan to use.
C11-15 Alketh-7 does not heighten photosensitivity, so it will not make skin more prone to sunburn. It also has a low likelihood of clogging pores which makes it a practical option for acne-prone users.
Potential Side Effects/Adverse Reactions
Reactions to topical C11-15 Alketh-7 differ from person to person. The following points list potential side effects that can occur, though most people will not encounter them when the ingredient is used at standard cosmetic concentrations.
- Skin irritation
- Contact dermatitis in individuals already sensitized to polyethylene glycols or fatty alcohols
- Mild stinging on compromised or freshly exfoliated skin
- Eye irritation if the product accidentally gets into the eyes
- Dryness when used in very high amounts or in rinse-off cleansers on already dry skin
If any of these effects occur discontinue use and consult a medical professional or dermatologist.
Comedogenic Rating
Rating: 1 / 5
C11-15 Alketh-7 is a water soluble emulsifier that easily rinses away and does not create an occlusive film, giving it a very low likelihood of blocking pores. Its molecular structure keeps it moving with the water phase rather than settling into sebaceous plugs, which is why formulators view it as practically non-comedogenic. Because it is typically used at small percentages and is not oily in itself, most acne-prone users should tolerate it well.
Keep in mind the overall formula matters: if C11-15 Alketh-7 appears alongside heavy plant butters or waxes the final product’s pore-clogging potential could rise even though the emulsifier alone rates a 1.
Summary
C11-15 Alketh-7’s main job is to emulsify, meaning it locks water and oil together so creams, lotions and serums stay smooth and stable. It does this through its dual-natured molecule: the fatty alcohol end loves oil while the ethoxylated end loves water, letting it sit at the interface and keep the mix homogenous.
You will find it in a steady stream of everyday products like lightweight moisturizers, sunscreens and leave-on conditioners. It is not a headline-grabbing ingredient yet it remains a quiet workhorse that formulators rely on when they want dependable performance without greasiness.
Safety reviews show it is well tolerated with a low risk of irritation or comedogenicity when used at normal cosmetic levels. Even so, individual skin can react to almost anything so doing a simple patch test with any new product is always a smart move.