Dihydroxyethyl Tallowamine Dioleate: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: June 27, 2025
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We verify all information on this page using publicly available nomenclature standards from The Personal Care Products Council (PCPC), the European Commission's CosIng database and documentation provided directly by ingredient manufacturers. Our analysis is based on technical data from these sources to ensure accuracy and reliability.

What Is Dihydroxyethyl Tallowamine Dioleate?

Dihydroxyethyl Tallowamine Dioleate is a conditioning agent made from animal-derived tallow fatty acids that have been reacted with ethylene oxide to create N,N-di-2-hydroxyethyl tallowamine, then esterified with oleic acid to form the dioleate. The resulting molecule has both water-loving and oil-loving parts, which helps it deposit evenly on hair. This type of chemistry first found use in fabric softeners during the mid-20th century, and formulators soon discovered that its softening ability also benefited hair care products. Today it is produced in large reactors where purified tallow fatty acids are combined with ethylene oxide under controlled temperature and pressure, followed by a reaction step with oleic acid. After neutralization and purification the ingredient is supplied as a viscous liquid that blends easily with other cosmetic raw materials. You will most often see it in rinse-off and leave-in conditioners, shampoos, hair masks, color-protecting treatments and some styling creams.

Dihydroxyethyl Tallowamine Dioleate’s Cosmetic Benefits/Uses

This ingredient serves a single but important role in cosmetics: hair conditioning. It forms a thin, smooth layer over each strand which reduces static, makes detangling easier and leaves hair feeling softer and more manageable. The lipid-rich coating also helps lock in moisture so hair looks shinier and less frizzy after styling.

Who Can Use Dihydroxyethyl Tallowamine Dioleate

This ingredient is generally well tolerated by all scalp and hair types, including dry, oily and color-treated hair. People with very sensitive or allergy-prone skin should proceed with caution since it is an animal-derived fatty amine that could trigger irritation in rare cases.

Because it is manufactured from tallow obtained from animal fat it is not suitable for vegans or vegetarians who avoid animal-sourced ingredients.

No specific warnings exist for those who are pregnant or breastfeeding when the ingredient is used topically in rinse-off or leave-in hair products. That said this is not medical advice and anyone who is pregnant or nursing should review new products with a healthcare professional first to be safe.

Dihydroxyethyl Tallowamine Dioleate is not known to cause photosensitivity so normal sun exposure practices apply. Individuals following religious or ethical guidelines that restrict animal by-products may also wish to avoid it.

Potential Side Effects/Adverse Reactions

Side effects from topical use of Dihydroxyethyl Tallowamine Dioleate vary from person to person. The points below list potential reactions but they are uncommon when the ingredient is properly formulated and used as directed.

  • Mild scalp or skin irritation such as redness or itching
  • Allergic contact dermatitis in those sensitive to fatty amines or animal-derived components
  • Eye irritation if the product accidentally gets into the eyes
  • Product buildup that can leave hair feeling heavy or greasy when overused

If any adverse reaction occurs discontinue use and seek medical advice if symptoms persist or worsen.

Comedogenic Rating

Rating: 2 out of 5

Dihydroxyethyl Tallowamine Dioleate contains long-chain fatty components derived from tallow and oleic acid, which have a slight tendency to clog pores when left on facial skin. However, its primary use is in rinse-off or hair-focused leave-in products, so the chance of it lingering on pore-rich areas is low. For most people this means minimal risk of breakouts.

Overall it can be considered reasonably suitable for acne-prone users, especially when applied only to the hair and rinsed out as directed.

If a leave-in product drips onto facial skin during styling, washing it off promptly will reduce any chance of pore congestion.

Summary

Dihydroxyethyl Tallowamine Dioleate is a hair-conditioning agent that smooths the cuticle, cuts down static and helps lock in moisture. Its dual water-loving and oil-loving structure lets it cling lightly to hair, forming a thin layer that improves softness, shine and manageability.

While effective, it is not a household name because many formulators now opt for synthetic quaternary conditioners that meet vegan preferences. Still, you will find it in certain traditional or cost-effective conditioners, masks and shampoos where its softening feel is valued.

Safety data show it is generally low-irritation when used as intended, with side effects limited to rare cases of sensitivity. As with any new cosmetic, performing a quick patch test on skin behind the ear or inner arm is a smart precaution.

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