What Is C11-15 Pareth-3?
C11-15 Pareth-3 is a nonionic surfactant made by reacting medium-chain fatty alcohols that contain 11 to 15 carbon atoms with roughly three units of ethylene oxide. The fatty alcohols usually come from coconut, palm or other plant oils, though they can also be made in a lab. This gentle chemical change, called ethoxylation, turns otherwise oily alcohols into a water-loving ingredient that mixes well with both oils and water.
Nonionic surfactants like C11-15 Pareth-3 started appearing in personal care products in the 1950s as formulators looked for milder options than traditional soaps. Over the years its balanced cleaning power and low skin irritation potential have made it a common pick for modern cosmetics.
You will most often see C11-15 Pareth-3 in rinse-off products such as shampoos, body wash and facial cleansers. It can also show up in lotions, creams, makeup removers and exfoliating scrubs where it helps keep the formula stable and easy to spread.
C11-15 Pareth-3’s Cosmetic Benefits/Uses
This versatile ingredient supports a formula in two key ways
- Cleansing: Its surfactant nature loosens dirt, excess oil and product buildup so they rinse away easily. Because it is nonionic it tends to be milder than many sulfates, helping cleansers work without leaving skin tight or hair overly stripped.
- Emulsifying: It helps oil and water blend into a uniform mixture, preventing separation in creams, lotions and cleansers. A stable emulsion feels smoother, spreads evenly and delivers active ingredients more consistently.
Who Can Use C11-15 Pareth-3
Because C11-15 Pareth-3 is a mild nonionic surfactant it is generally suitable for normal, oily, combination and even sensitive skin types. Its gentle cleansing action helps remove buildup without the tight feeling harsher detergents can leave behind. Those with very dry or compromised skin may prefer formulas where this ingredient is paired with richer moisturizers to avoid any chance of extra dryness.
The ingredient itself is typically produced from coconut, palm or fully synthetic sources so it contains no animal derived materials. As long as the finished product has not been tested on animals it can fit into vegan and vegetarian lifestyles. If palm sourcing is a concern, look for brands that disclose the use of certified sustainable palm oil.
C11-15 Pareth-3 has no known hormonal activity and is not absorbed in meaningful amounts through intact skin, so it is not expected to pose a risk during pregnancy or while breastfeeding. This is not medical advice; anyone who is pregnant or nursing should review new skincare products with a qualified healthcare professional first.
The ingredient does not increase photosensitivity and does not interact with sunlight, so routine daytime use does not call for extra sun protection beyond what you would normally wear.
Potential Side Effects/Adverse Reactions
Responses to any cosmetic ingredient can vary from person to person. The effects listed below are possible yet uncommon when C11-15 Pareth-3 is used at the levels typically found in personal care products that follow good manufacturing practices.
- Mild skin irritation
- Transient stinging on very sensitive or broken skin
- Eye irritation if the product accidentally gets into the eyes
- Dryness or a squeaky feel if used in a formula with little to no added emollients
- Contact allergy though this is rare
If you notice redness, itching or any prolonged discomfort stop using the product and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 1 / 5
C11-15 Pareth-3 is a water-soluble nonionic surfactant that rinses off easily and does not leave a heavy film on skin, so it has very little tendency to block pores. Published safety assessments and anecdotal reports show no meaningful link between this ingredient and acne formation, which is why it earns a low score of 1 rather than a perfect 0. In leave-on products the risk is still minimal but rises slightly because any residue remains on the skin.
With such a low rating this ingredient is generally suitable for people who are prone to breakouts.
The chance of clogged pores is even lower when the ingredient appears in rinse-off formulas like cleansers or shampoos that spend limited time on the skin.
Summary
C11-15 Pareth-3 is a mild surfactant that cleanses by surrounding oil and grime so they wash away easily, and it doubles as an emulsifier that helps oil and water stay mixed for a smoother stable product. These two roles make it a reliable backbone in many everyday formulas.
While not as buzzworthy as exotic plant extracts or new actives, this ingredient is a quiet workhorse found in a wide range of shampoos body washes facial cleansers and some lotions because it offers consistent performance at a reasonable cost.
Decades of research and practical use show C11-15 Pareth-3 is safe at the levels used in cosmetics with irritation or allergy being uncommon and usually mild. As with any new product a quick patch test is wise so you can spot any personal sensitivity before applying it more broadly.