Ingredient review

PEG-6 Undecylenate

INCI: PEG-6 Undecylenate

A gentle cleansing and odor-fighting ingredient that helps keep products stable and skin fresh, but may not suit ultra-sensitive skin in high concentrations.

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In plain English

PEG-6 Undecylenate is a semi-synthetic ingredient that helps clean skin and control body odor without harshness. It works by trapping odor-causing compounds and helping other ingredients mix together smoothly. You'll find it in deodorants, body washes, and some face cleansers. It's generally well-tolerated, but if you have very sensitive skin, you might want to patch-test products with higher amounts.

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.

Risk flags are low for most users, though the finished product can still irritate.

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

Quick decision guide

Useful, but context matters

PEG-6 Undecylenate is generally a lower-concern ingredient when the full formula suits your skin.

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 PEG-6 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

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

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

PEG-6 Undecylenate is a polyethylene glycol (PEG) derivative of undecylenic acid, a fatty acid naturally found in castor oil. It is produced through a controlled chemical process that makes it water-soluble and mild on skin.

How it works

In a cosmetic product, PEG-6 Undecylenate acts as a surfactant (cleansing agent) and emulsifier (helps oil and water mix). It also has mild antimicrobial properties that help reduce odor-causing bacteria on the skin's surface, making it useful in deodorants and body cleansers.

Pros

Odor control without harshness

Helps reduce underarm and body odor by targeting bacteria, but is much milder than traditional antiperspirants or alcohol-based deodorants.

Gentle cleansing action

Works as a mild surfactant that cleanses without stripping the skin's natural moisture barrier, making it suitable for daily use.

Cons and cautions

Potential for trace impurities

As a PEG derivative, it may contain trace levels of ethylene oxide or 1,4-dioxane if not manufactured under strict purification standards. Reputable brands ensure these are removed.

Not ideal for very sensitive skin at high levels

In leave-on products with high concentrations, some individuals with extremely reactive skin may experience mild redness or stinging.

Best for

  • People looking for a gentle deodorant or body wash that fights odor
  • Those with normal to combination skin who want effective but mild cleansing

Use caution if

  • Individuals with known sensitivity to PEG compounds or undecylenic acid derivatives

Usage tips

If using a deodorant with PEG-6 Undecylenate, apply to clean, dry skin for best odor control.
Patch-test a new product on your inner arm before full use if you have sensitive skin.

Safety summary

PEG-6 Undecylenate is considered safe for use in cosmetics at typical concentrations. The main safety consideration is the potential for trace impurities (ethylene oxide, 1,4-dioxane) in poorly manufactured batches, but reputable suppliers and brands ensure these are removed through purification. Skin irritation is rare at low concentrations.

Research notes

Research on undecylenic acid derivatives supports their antimicrobial and odor-reducing properties. PEG-6 Undecylenate itself has limited direct clinical studies, but its safety profile is supported by broader reviews of PEG compounds and undecylenic acid by the Cosmetic Ingredient Review panel.

Common label clues

Typical concentration
0.5% to 5% in rinse-off products; lower in leave-on formulas
Regulatory status
Approved for use in cosmetics in the EU, US, and many other regions. The Cosmetic Ingredient Review (CIR) panel has evaluated PEG compounds and found them safe when formulated to minimize impurities.
Common uses
Deodorants, Body washes, Facial cleansers, Leave-on creams
Environmental note
PEG-6 Undecylenate is biodegradable under standard wastewater treatment conditions, but as with all PEGs, its production involves petrochemical-derived ethylene oxide.

Good to know

  • PEG-6 Undecylenate is often combined with other deodorizing ingredients like zinc ricinoleate for enhanced odor control.
  • It is considered biodegradable and is not classified as a persistent environmental pollutant.

Common questions

What is PEG-6 Undecylenate in beauty products?

PEG-6 Undecylenate is a semi-synthetic ingredient that helps clean skin and control body odor without harshness. It works by trapping odor-causing compounds and helping other ingredients mix together smoothly. You'll find it in deodorants, body washes, and some face cleansers. It's generally well-tolerated, but if you have very sensitive skin, you might want to patch-test products with higher amounts.

What does PEG-6 Undecylenate do in a beauty product?

In a cosmetic product, PEG-6 Undecylenate acts as a surfactant (cleansing agent) and emulsifier (helps oil and water mix). It also has mild antimicrobial properties that help reduce odor-causing bacteria on the skin's surface, making it useful in deodorants and body cleansers.

Is PEG-6 Undecylenate safe for most people?

PEG-6 Undecylenate is considered safe for use in cosmetics at typical concentrations. The main safety consideration is the potential for trace impurities (ethylene oxide, 1,4-dioxane) in poorly manufactured batches, but reputable suppliers and brands ensure these are removed through purification. Skin irritation is rare at low concentrations.

Who should be careful with PEG-6 Undecylenate?

Individuals with known sensitivity to PEG compounds or undecylenic acid derivatives

Research sources

Cosmetic Ingredient Review – Safety of PEGsOpenPubMed – Undecylenic acid antimicrobial activityOpenEuropean Chemicals Agency – PEG-6 Undecylenate infoOpen

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.