What Is Triethanolamine Sesquistearate?
Triethanolamine Sesquistearate is a blend of esters made when stearic acid, a fatty acid from plant or animal fats, reacts with triethanolamine, a compound often made from ethylene oxide and ammonia. The result is a creamy, wax-like material that mixes well with both water and oil.
The cosmetic world began paying attention to this ingredient in the mid-20th century when formulators looked for gentle, multi-purpose agents that could soften skin and keep products stable. Because it can both moisturize and help bind oil and water, it found a home in lotions and creams that needed a smooth, rich feel.
Manufacturing starts with purified stearic acid that is heated and combined with liquid triethanolamine. Controlled temperature and mixing turn the two into mono- and di-esters. After cooling, the material is filtered, milled to the right texture, and tested for purity before being sent to cosmetic labs.
You will most often see Triethanolamine Sesquistearate in day and night moisturizers, body lotions, hand creams, makeup primers, creamy masks, and some anti-aging blends that aim for a plush skin feel.
Triethanolamine Sesquistearate’s Cosmetic Benefits/Uses
Formulators choose this ingredient because it offers a mix of feel-good and skin-loving perks.
- Skin Conditioning: Forms a light film on the surface that helps skin feel softer and smoother while reducing rough patches
- Emollient: Fills in tiny gaps between skin cells to boost suppleness and create a velvety after-touch that many users enjoy
Who Can Use Triethanolamine Sesquistearate
Most skin types—including normal, dry and combination—handle Triethanolamine Sesquistearate without trouble because the ingredient is mild and moisturizing. People with very oily or acne-prone skin might find it a bit heavy, and those with highly reactive or compromised skin should proceed carefully since any film-forming agent can occasionally trap heat or irritants close to the surface.
The stearic acid portion of the molecule can be sourced from plants or animal fat. If a product is labeled as vegan or clearly states it uses vegetable-derived stearic acid, then both vegans and vegetarians can feel comfortable using it. When the sourcing is not specified, its suitability for a strictly plant-based lifestyle is uncertain.
No studies have linked topical Triethanolamine Sesquistearate with problems during pregnancy or while breastfeeding. Still, this is not medical advice and anyone who is pregnant or nursing should show the full product ingredient list to a qualified health professional before use.
The ingredient does not cause photosensitivity, so it will not make skin more vulnerable to sunburn. It is also odorless and free of essential oils, which makes it a quiet team player in fragrance-free formulas.
Potential Side Effects/Adverse Reactions
Reactions to Triethanolamine Sesquistearate vary from person to person. The points below outline possible side effects, but most users will not experience them when the ingredient is used at standard cosmetic levels.
- Mild skin irritation such as redness itching or a light burning sensation, especially on sensitive or broken skin
- Allergic contact dermatitis in individuals already sensitized to amine compounds
- Eye irritation or watering if the product accidentally migrates into the eyes
- Surface bumps or clogged pores in very oily skin when used in rich leave-on products
If any of these effects appear, discontinue use immediately and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 2 out of 5. Triethanolamine Sesquistearate contains stearic acid esters that can feel rich and slightly occlusive yet they do not rank as highly pore clogging as pure heavy oils. Most people will not notice breakouts, but those already struggling with frequent blemishes might see an uptick if the rest of the formula is also thick or oily. In rinse-off products its tendency to block pores is very low, whereas in dense leave-on creams the risk climbs a bit. Overall it is generally acceptable for acne-prone skin though lighter textures are preferable.
No additional special concerns beyond choosing an overall formula that suits your skin’s oil level.
Summary
Triethanolamine Sesquistearate works as a skin-conditioning emollient that softens rough spots and leaves a velvety finish. It does this by forming light mono- and di-ester films that smooth the surface and reduce transepidermal water loss. While not a headline ingredient it is a steady backstage player in moisturizers, primers and masks where a plush feel is desired.
Safety data show it is well tolerated at the low percentages used in cosmetics with only rare irritation or allergy reports. Still, skin is individual so try a small patch first when exploring any new product that lists it to ensure personal compatibility.