What Is Steareth-11?
Steareth-11 is a synthetic ingredient made by reacting stearyl alcohol, a fat derived from vegetable oils, with ethylene oxide units. The resulting material is a waxy solid that easily dissolves in water and oil, giving it a flexible nature prized in modern formulas. First explored in the 1970s as chemists searched for gentler cleansers, it soon found a place in skin care and hair care for its knack at mixing oil and water. Production starts with plant based stearyl alcohol, which is purified, then blended with a controlled number of ethylene oxide molecules, in this case an average of eleven. The finished ingredient is filtered, dried and milled into a fine powder or flakes ready for use. You will commonly spot it in facial cleansers, lightweight moisturizers, makeup removers, masks, sun care lotions and some conditioning hair products where a smooth, even texture is needed.
Steareth-11’s Cosmetic Benefits/Uses
Formulators rely on Steareth-11 for more than one job in a single bottle.
- Cleansing: Its surface activity lifts dirt, oil and makeup from skin or hair allowing them to be rinsed away without harsh scrubbing
- Emulsifying: It binds water and oil into a stable blend so creams stay smooth, lotions stay fluid and the product does not split on the shelf
Who Can Use Steareth-11
Steareth-11 is generally well tolerated by most skin types including oily, dry, combination, normal and even many sensitive complexions, thanks to its mild cleansing action and low use levels. Very reactive or compromised skin may still find any ethoxylated ingredient a bit irritating so patchy redness is possible in rare cases.
The stearyl alcohol used to make Steareth-11 is almost always sourced from vegetable oils which makes the finished material suitable for vegans and vegetarians. Those following a strict plant based lifestyle may still want to confirm the supplier’s sourcing policy to ensure no animal derived fallback is used.
No specific warnings exist for pregnant or breastfeeding women regarding topical Steareth-11. Regulatory bodies consider it safe in the percentages used in cosmetics but this is not medical advice and anyone who is pregnant or nursing should run all skincare choices past a qualified doctor just to be on the safe side.
The ingredient does not increase photosensitivity so it will not make skin more prone to sunburn. It also rinses cleanly which helps reduce residue related buildup on scalp or skin.
Potential Side Effects/Adverse Reactions
Side effects and reactions to the topical use of Steareth-11 can vary from person to person. The following is a list of potential issues only and most users will not experience them when the ingredient is formulated and used correctly.
- Mild skin irritation such as redness or itching, especially on very sensitive skin
- Transient stinging if applied to broken or abraded areas
- Contact dermatitis in individuals allergic to ethoxylated surfactants
- Eye irritation if a product accidentally contacts the eyes before being rinsed away
- Very rare allergic reaction presenting as swelling or hives
If any of these reactions occur stop using the product immediately and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 1/5
Steareth-11 has a very low tendency to clog pores because it is primarily a water-soluble surfactant that is usually rinsed off the skin. While its stearyl backbone is fatty, the addition of eleven ethylene oxide units makes the molecule highly dispersible in water which limits any heavy, pore-blocking film. Products that are left on the skin may pose a slightly higher risk, but the overall profile remains low.
Most acne-prone users should tolerate Steareth-11 without additional breakouts, especially in cleansers, light lotions or masks that are removed after a short contact time.
Comedogenicity can be influenced by the entire formula, so how Steareth-11 is combined with other ingredients and in what concentration matters more than its presence alone.
Summary
Steareth-11 acts mainly as a gentle cleanser and an emulsifier. Its surface-active nature lifts oil, dirt and makeup so they can be washed away, while its balanced water-loving and oil-loving portions keep oil and water blended for smooth stable creams and lotions.
It is a workhorse ingredient that shows up regularly in mainstream facial cleansers, lightweight moisturizers and some hair products, though newer green-market emulsifiers have stolen a bit of its spotlight.
Regulatory reviews consider Steareth-11 safe at the levels used in cosmetics and real-world reports of problems are rare. As with any new product it is wise to run a small patch test first so you can be sure it agrees with your unique skin.