What Is Steareth-3?
Steareth-3 is a synthetic ingredient made by attaching an average of three units of ethylene oxide to stearyl alcohol, a fatty alcohol that can come from plant oils such as coconut or palm. The result is a waxy, off-white solid that melts easily into liquid formulations. Ethoxylated fatty alcohols like Steareth-3 were first introduced to personal care labs in the 1950s when chemists looked for milder alternatives to soap-based surfactants. Today manufacturers create Steareth-3 through a controlled reaction called ethoxylation, where stearyl alcohol is mixed with ethylene oxide under heat and pressure, then purified to remove residues.
Because it helps water and oil mix, Steareth-3 shows up in a wide range of products. You will often find it in facial cleansers, makeup removers, body lotions, moisturizers, leave-on hair conditioners, wash-off masks and lightweight serums. It is also common in sun care and self-tanning formulas where a stable oil-in-water blend is key.
Steareth-3’s Cosmetic Benefits/Uses
In formulas Steareth-3 plays two main roles that improve texture and performance:
- Emulsifying: It acts like a bridge between water and oil, helping them stay blended so creams do not separate over time. This gives products a smooth, even feel and makes active ingredients spread more uniformly on skin or hair.
- Cleansing: Its surfactant nature lifts away dirt, makeup and excess sebum, allowing them to rinse off easily without leaving a heavy residue. This makes it useful in gentle facial washes and micellar products that aim to clean while keeping skin soft.
Who Can Use Steareth-3
Steareth-3 is generally considered suitable for most skin types including oily, dry or combination skin thanks to its mild cleansing action and low likelihood of clogging pores. People with very sensitive or compromised skin should proceed with caution, as any surfactant can occasionally trigger irritation in those groups.
The ingredient is made from stearyl alcohol that is typically sourced from plant oils or produced synthetically, so it is compatible with vegetarian and vegan lifestyles when the finished formula contains no added animal derivatives.
Current safety data does not flag Steareth-3 as a risk for pregnant or breastfeeding women, but this information is not medical advice. Anyone who is expecting or nursing should run their entire skincare routine past a qualified healthcare provider for personalized guidance.
Steareth-3 does not increase photosensitivity and can be used in both day and night products without special sun precautions. It also plays well with common actives like niacinamide, ceramides and gentle exfoliating acids, making it a flexible choice for layered routines.
Potential Side Effects/Adverse Reactions
Side effects and reactions to the topical use of Steareth-3 vary from person to person. The points below list potential issues that may occur, though most users will not experience them when the ingredient is properly formulated and used as directed.
- Mild skin irritation such as redness, itching or a slight stinging sensation
- Contact dermatitis in individuals allergic to ethoxylated surfactants or fatty alcohols
- Eye irritation if cleanser or lotion accidentally gets into the eyes
- Dryness or tightness when used at high concentrations without adequate moisturizers
- Very low risk of trace 1,4-dioxane contamination if manufacturing purification is inadequate
If any negative reaction develops stop using the product immediately and seek advice from a dermatologist or healthcare professional.
Comedogenic Rating
Rating: 1 / 5
Steareth-3 scores a low 1 because its structure is mostly water loving, so it rinses off easily and does not sit on skin long enough to block pores. Unlike heavier fatty alcohols it is present at small percentages and is usually paired with lightweight emollients that further cut the risk of buildup.
This means Steareth-3 is generally fine for acne-prone or breakout-prone skin, though the overall formula and how often you use it still matter. Very sensitive or highly congested skin types should keep an eye on how their skin responds since individual tolerance can vary.
Formulators sometimes combine Steareth-3 with richer oils to improve spreadability; if the finished product feels heavy that heaviness is more likely to come from those oils than from Steareth-3 itself.
Summary
Steareth-3 is an ethoxylated fatty alcohol that mainly acts as an emulsifier and a mild cleanser. Its dual nature lets it hold water and oil together creating stable creams lotions and cleansers, while its surfactant side lifts away dirt and makeup without stripping skin.
You will see it in a wide range of mainstream and indie products because it is affordable, easy to formulate with and offers reliable performance. It may not be a buzzworthy hero ingredient, but formulators keep reaching for it because it quietly does its job and keeps textures smooth.
Current safety reviews place Steareth-3 in the low risk category when used at typical cosmetic levels. Still, every skin is different, so whenever you try a new product that contains Steareth-3 or any unfamiliar ingredient, do a quick patch test first just to be safe.