Ingredient review
Dimethicone PEG-7 Undecylenate
INCI: DIMETHICONE PEG-7 UNDECYLENATE
A gentle silicone emulsifier that helps products spread smoothly and feel silky, with very low irritation potential.
In plain English
Dimethicone PEG-7 Undecylenate is a hybrid ingredient that combines silicone with a water-loving PEG chain and a fatty acid from castor oil. It acts as a bridge between water and oil in a formula, allowing them to mix into a stable cream or lotion. It also leaves a light, silky feel on skin or hair without being heavy or greasy.
Review score
Safety, usefulness, and evidence
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
Quick decision guide
Useful, but context matters
Dimethicone PEG-7 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.
- Step 1Start with the score, then check the irritation and clogging risk before judging Dimethicone PEG-7 Undecylenate.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- 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
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
A semi-synthetic silicone derivative that functions as an emulsifier and skin conditioner. It is made by attaching a PEG (polyethylene glycol) chain and undecylenic acid (a fatty acid from castor oil) to dimethicone, a common silicone.
How it works
The PEG chain makes the silicone water-soluble, so it can help disperse oils into water-based formulas. Once applied, it forms a thin, breathable film on the skin or hair that reduces friction, improves spreadability, and leaves a smooth, non-sticky finish.
Pros
Silky, lightweight feel
Creates a smooth, non-greasy finish on skin and hair, making it ideal for lightweight lotions and conditioners.
Very gentle on skin
Rated low for both irritation and comedogenicity, so it's unlikely to cause breakouts or stinging even for sensitive skin.
Cons and cautions
Potential PEG impurities
PEG compounds can be contaminated with 1,4-dioxane during manufacturing, though high-quality suppliers remove it through purification.
Environmental persistence
As a silicone derivative, it is not readily biodegradable and may contribute to bioaccumulation in water systems.
Best for
- People with normal to oily skin who want lightweight, non-greasy moisturizers
- Anyone looking for a gentle emulsifier in fragrance-free or sensitive-skin formulas
Use caution if
- Those who strictly avoid silicones or PEG compounds for personal or environmental reasons
Usage tips
Safety summary
Dimethicone PEG-7 Undecylenate is considered safe for topical use at typical cosmetic concentrations. The main concern is the potential presence of 1,4-dioxane, a byproduct of PEG manufacturing, but reputable suppliers remove it. Overall, it has a low irritation and comedogenic profile.
Research notes
Safety assessments by the Cosmetic Ingredient Review (CIR) panel have found PEG-modified silicones to be safe as used in cosmetics. No specific studies on this exact compound were found, but its structure is similar to other well-studied PEG silicones. Evidence is based on general ingredient class safety.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the US, EU, and most other regions. The EU restricts PEG compounds to those with low 1,4-dioxane levels, but no specific ban exists for this ingredient.
- Common uses
- Moisturizers, Sunscreens, Hair conditioners, Makeup removers
- Environmental note
- Silicone derivatives like this one are not easily broken down in nature. They can accumulate in aquatic environments, so some consumers prefer biodegradable alternatives.
Good to know
- This ingredient is often used in 'water-in-silicone' emulsions, which are common in long-wear makeup and sunscreens.
- It is considered a 'volatile' silicone, meaning it evaporates slightly on the skin, contributing to a dry-touch feel.
Common questions
What is Dimethicone PEG-7 Undecylenate in beauty products?
Dimethicone PEG-7 Undecylenate is a hybrid ingredient that combines silicone with a water-loving PEG chain and a fatty acid from castor oil. It acts as a bridge between water and oil in a formula, allowing them to mix into a stable cream or lotion. It also leaves a light, silky feel on skin or hair without being heavy or greasy.
What does Dimethicone PEG-7 Undecylenate do in a beauty product?
The PEG chain makes the silicone water-soluble, so it can help disperse oils into water-based formulas. Once applied, it forms a thin, breathable film on the skin or hair that reduces friction, improves spreadability, and leaves a smooth, non-sticky finish.
Is Dimethicone PEG-7 Undecylenate safe for most people?
Dimethicone PEG-7 Undecylenate is considered safe for topical use at typical cosmetic concentrations. The main concern is the potential presence of 1,4-dioxane, a byproduct of PEG manufacturing, but reputable suppliers remove it. Overall, it has a low irritation and comedogenic profile.
Who should be careful with Dimethicone PEG-7 Undecylenate?
Those who strictly avoid silicones or PEG compounds for personal or environmental reasons
Research sources
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.