What Is Steareth-16?
Steareth-16 is a synthetic compound classified as a polyethylene glycol ether of stearyl alcohol. In simpler terms, chemists start with stearyl alcohol, a fatty alcohol commonly sourced from plant oils such as coconut or palm, and attach about 16 units of ethylene oxide to create a water-loving chain. This transformation turns an oily raw material into an ingredient that happily mixes oil and water, a property prized in modern skin and hair formulas.
The use of ethoxylated fatty alcohols in cosmetics dates back to the mid-20th century when formulators needed reliable, skin-friendly emulsifiers for creams and lotions. As formulations advanced, Steareth-16 found favor for its balance of mildness, stability and versatility, earning a place in moisturizers, facial cleansers, makeup removers, micellar waters, sunscreens, hair conditioners and wash-off masks. Production involves controlled ethoxylation: stearyl alcohol reacts with ethylene oxide gas in a pressurized reactor, the process monitored to stop at roughly sixteen repeating units. The final material is purified, tested for residual impurities and supplied as a waxy solid or flakes ready to melt into cosmetic bases.
Steareth-16’s Cosmetic Benefits/Uses
Formulators include Steareth-16 because it performs a few essential jobs that improve texture, stability and cleansing power.
- Cleansing: Its surfactant nature helps loosen and lift dirt, excess oil and makeup from skin or hair so they can be rinsed away without harsh scrubbing
- Emulsifying: Steareth-16 binds water and oil into smooth, uniform emulsions, preventing separation and giving creams or lotions their silky, spreadable feel
Who Can Use Steareth-16
Most skin types, including normal, dry, combination and oily, tolerate Steareth-16 well because it is considered a mild, non-sensitizing surfactant. Sensitive skin generally does fine too, though very reactive individuals may prefer to limit leave-on exposure and watch for redness or stinging, as with any new ingredient.
Steareth-16 is made from fatty alcohol that can be sourced from plants or synthetically produced, so it can be suitable for vegans and vegetarians when the manufacturer confirms the starting material is plant derived and no animal by-products are used during processing.
Pregnant or breastfeeding women are not known to face special risks from topical Steareth-16. Current research shows no evidence of hormonal activity or systemic absorption at levels used in cosmetics. Still, this is not medical advice; anyone who is expecting or nursing should review all personal care products with their physician to be safe.
The ingredient does not cause photosensitivity, so it will not make skin more prone to sunburn. It is also fragrance free and nonvolatile, making it unlikely to trigger scent-related headaches or respiratory irritation.
Potential Side Effects/Adverse Reactions
Reactions to topical Steareth-16 vary from person to person. The following list outlines potential side effects that could occur but are uncommon when products are properly formulated and used as directed.
- Mild skin irritation such as redness itching or tingling, especially on compromised or highly sensitive skin
- Contact dermatitis in individuals allergic to ethoxylated surfactants
- Eye irritation if the product accidentally gets into the eyes before rinsing
- Dryness or tightness when high concentrations remain on the skin without adequate moisturizers
- Potential trace contamination with 1,4-dioxane if manufacturing purification is inadequate
If any discomfort or reaction occurs stop using the product immediately and consult a healthcare professional if symptoms persist.
Comedogenic Rating
Rating: 1/5. Although Steareth-16 is derived from stearyl alcohol, the added ethylene oxide units make it far more water soluble, so it does not sit on skin in the heavy, pore-clogging way that some fatty alcohols can. Most formulas also include it at low levels or in rinse-off products, further lowering any clogging potential. For these reasons, it is generally considered suitable for people prone to acne or breakouts.
Because comedogenicity can rise when an ingredient is used at very high percentages in thick, occlusive creams, anyone extremely prone to congestion may prefer lighter textures that rinse away or absorb quickly.
Summary
Steareth-16’s main roles are cleansing and emulsifying. Its surfactant nature lowers surface tension to lift away oil and debris, while its balanced lipophilic and hydrophilic ends bind water with oil to keep lotions, creams or makeup removers stable, silky and uniform.
It is a quiet workhorse rather than a headline grabbing ingredient, but formulators appreciate its reliability in everything from facial cleansers to sunscreens so you will often find it near the middle of an ingredient list.
Current data show it is low risk for skin irritation, non-sensitizing for most users and not linked to systemic toxicity when properly purified, though trace 1,4-dioxane is monitored by manufacturers. As with any new cosmetic, patch test first to ensure personal compatibility before adding a Steareth-16 product to your routine.