Ingredient review

TEA-Undecylenate

INCI: TEA-Undecylenate

An effective cleansing and antimicrobial agent, but may be drying for sensitive or dry skin types.

beautyskincarecleansing agent

In plain English

TEA-Undecylenate is a soap-like ingredient that helps remove dirt, oil, and bacteria from the skin. It is made by combining undecylenic acid (from castor oil) with triethanolamine. While it cleans well, it can strip the skin of its natural oils, so it is best used in rinse-off products like bar soaps or facial washes, not in leave-on formulas.

Review score

Safety, usefulness, and evidence

3.8Good
3.8/ 5

Potentially useful with some tradeoffs

The evidence base is useful, but some claims depend heavily on the formula.

Main practical flags: irritation is moderate; clogging risk is low.

Source
semi synthetic
Evidence
moderate
Irritation
moderate
Clogging risk
low
How reviews are scored

Quick decision guide

Useful, but context matters

TEA-Undecylenate can be useful, but watch for some irritation potential.

Plain-English read

Treat this as a practical screening step before you compare products that contain this ingredient.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging TEA-Undecylenate.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.

Score terms in plain English

Irritation risk

moderate

Can bother some users, especially with frequent use, damaged skin, or strong companion ingredients.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

TEA-Undecylenate is a salt formed from undecylenic acid (a fatty acid from castor oil) and triethanolamine. It acts as a surfactant, meaning it helps water mix with oil and dirt so they can be rinsed away.

How it works

In a cosmetic product, TEA-Undecylenate reduces the surface tension of water, allowing it to penetrate and lift oils and debris from the skin. It also has mild antimicrobial properties, which can help reduce bacteria on the skin's surface.

Pros

Strong cleanser

Effectively removes excess oil, dirt, and makeup, making it ideal for oily skin types.

Antimicrobial properties

Helps reduce surface bacteria, which can be beneficial for acne-prone skin when used in a rinse-off cleanser.

Cons and cautions

Potential for dryness

Can strip the skin of natural oils, leading to tightness or irritation, especially with frequent use.

Not for sensitive skin

May cause stinging or redness in those with compromised skin barriers or conditions like rosacea.

Best for

  • People with oily or acne-prone skin looking for a deep cleanse
  • Those who prefer bar soaps or traditional cleansing bars

Use caution if

  • Individuals with dry, sensitive, or eczema-prone skin
  • Anyone using leave-on products where this ingredient is present

Usage tips

Use only in rinse-off products like soaps or face washes, not in leave-on creams or lotions.
Follow with a moisturizer to replenish hydration after cleansing.
If you have dry skin, limit use to once daily or alternate with a gentler cleanser.

Safety summary

Generally safe for use in rinse-off products at typical concentrations. However, it can be drying and irritating for sensitive skin. Avoid contact with eyes and broken skin.

Research notes

Studies on undecylenic acid derivatives show antimicrobial activity against fungi and bacteria. Human patch tests indicate low irritation potential in properly formulated products, but individual sensitivity varies.

Common label clues

Typical concentration
0.5% to 5% in rinse-off products
Regulatory status
Approved for use in cosmetics in the EU, US, and other major markets. The Cosmetic Ingredient Review (CIR) panel has evaluated related undecylenate salts as safe when formulated to be non-irritating.
Common uses
Bar soaps, Liquid cleansers, Facial washes
Environmental note
Castor oil is a renewable resource, but the triethanolamine component may have moderate aquatic toxicity. Rinse-off use minimizes environmental impact.

Good to know

  • Often found in combination with other surfactants to reduce irritation.
  • The undecylenic acid component is derived from castor oil, a renewable plant source.

Common questions

What is TEA-Undecylenate in beauty products?

TEA-Undecylenate is a soap-like ingredient that helps remove dirt, oil, and bacteria from the skin. It is made by combining undecylenic acid (from castor oil) with triethanolamine. While it cleans well, it can strip the skin of its natural oils, so it is best used in rinse-off products like bar soaps or facial washes, not in leave-on formulas.

What does TEA-Undecylenate do in a beauty product?

In a cosmetic product, TEA-Undecylenate reduces the surface tension of water, allowing it to penetrate and lift oils and debris from the skin. It also has mild antimicrobial properties, which can help reduce bacteria on the skin's surface.

Is TEA-Undecylenate safe for most people?

Generally safe for use in rinse-off products at typical concentrations. However, it can be drying and irritating for sensitive skin. Avoid contact with eyes and broken skin.

Who should be careful with TEA-Undecylenate?

Individuals with dry, sensitive, or eczema-prone skin Anyone using leave-on products where this ingredient is present

Research sources

Cosmetic Ingredient Review (CIR) - Safety Assessment of UndecylenatesOpenPubMed - Antimicrobial activity of undecylenic acidOpenINCI Database - TEA-UndecylenateOpen

Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.