What Is Steareth-5 Stearate?
Steareth-5 Stearate is a synthetic ingredient derived from stearic acid, a fatty acid most commonly found in vegetable fats like coconut or palm oil as well as animal fats. Chemically, it is a blend of stearyl alcohol combined with about five units of ethylene oxide, then esterified with stearic acid. The resulting molecule has both oil-loving and water-loving parts, which is why it behaves so well in emulsions.
The cosmetic industry began experimenting with ethoxylated fatty alcohols in the mid-20th century to improve the stability and feel of creams and lotions. Steareth-5 Stearate emerged as a reliable option because its relatively low ethoxylation level gives a balanced HLB value, making it versatile in both oil-in-water and water-in-oil systems. Large-scale production typically starts with plant-sourced stearyl alcohol, which is reacted with ethylene oxide under controlled heat and pressure. The intermediate is then reacted with stearic acid to form the final ester and purified to remove residual reactants.
You will most often see Steareth-5 Stearate in moisturizers, anti-aging creams, facial masks, sunscreens, makeup primers and cleansing balms. It is prized for creating smooth, stable textures that spread evenly on the skin without a greasy afterfeel.
Steareth-5 Stearate’s Cosmetic Benefits/Uses
This ingredient adds both functional performance and sensory appeal to topical formulas.
- Emulsifying: Its dual affinity allows oil and water to blend into a stable emulsion, preventing separation over time. This means creams stay uniform, feel silky and deliver active ingredients evenly with every use.
- Skin Conditioning: By forming a light, flexible film on the surface, Steareth-5 Stearate helps soften and smooth skin, enhances moisture retention and improves the overall feel of a product during application.
Who Can Use Steareth-5 Stearate
Because Steareth-5 Stearate is lightweight and non occlusive, it generally works well for normal, dry and combination skin. Oily or very acne prone complexions can usually tolerate it too thanks to its low comedogenic rating, though individuals highly sensitive to fatty alcohol derivatives may prefer to avoid it.
The ingredient is typically synthesized from plant based stearyl alcohol so it can be suitable for vegans and vegetarians if the finished product source is confirmed as plant derived. Some brands may still obtain stearic acid or stearyl alcohol from animal fat, so label readers who follow a strict vegan lifestyle should verify the supply chain.
No data indicate that Steareth-5 Stearate absorbs systemically or interferes with pregnancy or lactation. Current cosmetic safety assessments find it safe for topical use during these life stages. This is not medical advice and anyone who is pregnant or breastfeeding should consult a healthcare professional before starting a new skincare product.
The molecule does not photosensitize skin and does not increase sensitivity to sunlight. It also does not interfere with most actives, preservatives or fragrances, making it compatible with a wide range of formulations.
Potential Side Effects/Adverse Reactions
Responses to Steareth-5 Stearate can vary from person to person. The effects listed below are possible yet uncommon when the ingredient is used in a properly formulated cosmetic product.
- Mild skin irritation in individuals with a known sensitivity to ethoxylated compounds or fatty alcohol derivatives
- Contact dermatitis rarely reported in people with compromised skin barriers or pre existing eczema
- Eye stinging if products containing high concentrations are applied too close to the eye area
If discomfort, redness or any other adverse reaction develops discontinue use and seek medical advice
Comedogenic Rating
Rating: 1/5. Steareth-5 Stearate is a lightweight fatty alcohol ester that tends to sit on the skin surface without deeply blocking pores. Its molecular size and balanced oil-water affinity let it spread thinly, so it is far less likely to trap sebum or dead skin cells compared with heavier waxes or butters. For most acne-prone users this low rating means the ingredient is generally suitable, though overall formula and personal skin behavior still matter. If used in a product blended with highly occlusive oils the final pore-clogging potential may rise, so always judge the full ingredient list.
Summary
Steareth-5 Stearate acts mainly as an emulsifier and skin-conditioning agent, keeping oil and water mixed while laying down a soft breathable film that smooths and softens the skin. Its dual nature stems from the ethoxylated portion that loves water and the fatty stearate portion that loves oil, a combo that stabilizes creams and enhances their silky glide.
This ingredient is a solid workhorse rather than a buzzworthy star. You will spot it in many moisturizers, sunscreens and makeup primers but it rarely headlines marketing campaigns. Formulators appreciate it for reliability affordable cost and broad compatibility.
Safety reviews place Steareth-5 Stearate in the low-risk category for topical use with minimal irritation reports. As with any new skincare product a quick patch test on a small area is wise to confirm personal tolerance before regular use.