Ingredient review
Bis-Isobutyl PEG-13/Dimethicone Copolymer
INCI: BIS-ISOBUTYL PEG-13/DIMETHICONE COPOLYMER
A gentle silicone emulsifier that improves product texture and stability without common irritation concerns.
In plain English
This is a synthetic silicone ingredient that acts like a bridge between water and oil in skincare products. It helps keep the formula smooth and stable, so your lotion or cream doesn't separate. It's very mild on skin and unlikely to cause breakouts or irritation, making it a common choice for sensitive skin formulas.
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
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Bis-Isobutyl PEG-13/Dimethicone Copolymer 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 Bis-Isobutyl PEG-13/Dimethicone Copolymer.
- 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 silicone-based copolymer (a large molecule made of repeating units) modified with PEG (polyethylene glycol) and isobutyl groups. It is designed to help mix water and oil phases in a cosmetic product.
How it works
It sits at the boundary between water and oil droplets, reducing surface tension so they blend into a stable emulsion. This prevents the product from separating and gives a smooth, even texture when applied to skin.
Pros
Gentle on skin
Rated low for both irritation and comedogenicity, so it's unlikely to cause redness or breakouts even for sensitive skin.
Improves formula stability
Helps keep water and oil mixed, so your product stays consistent and effective from first use to last.
Cons and cautions
Synthetic origin
Made from petrochemicals, which may not align with natural or 'clean' beauty preferences.
Slippery feel
Can leave a slightly slick or silicone-like afterfeel that some people find less pleasant than oil-based alternatives.
Best for
- Anyone using lotions, creams, or sunscreens who wants a stable, smooth formula
- People with sensitive or acne-prone skin looking for a gentle emulsifier
Use caution if
- Those strictly avoiding all silicones or PEG compounds
Usage tips
Safety summary
Considered safe for cosmetic use at typical concentrations. Low irritation and comedogenic scores make it suitable for most skin types, including sensitive and acne-prone skin.
Research notes
Limited independent studies on this specific copolymer, but the broader class of PEG-modified silicones is well-studied and generally recognized as safe by cosmetic safety panels.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics globally, including by the FDA (US) and EU CosIng database, with no known restrictions at typical levels.
- Common uses
- Moisturizers, Sunscreens, Foundations, Serums
- Environmental note
- As a silicone derivative, it may not be biodegradable; however, its low concentration in products limits environmental impact.
Good to know
- PEG compounds are processed to remove impurities, making them safe for cosmetic use.
- This ingredient is often used in 'silicone-friendly' routines because it's a silicone itself.
Common questions
What is Bis-Isobutyl PEG-13/Dimethicone Copolymer in beauty products?
This is a synthetic silicone ingredient that acts like a bridge between water and oil in skincare products. It helps keep the formula smooth and stable, so your lotion or cream doesn't separate. It's very mild on skin and unlikely to cause breakouts or irritation, making it a common choice for sensitive skin formulas.
What does Bis-Isobutyl PEG-13/Dimethicone Copolymer do in a beauty product?
It sits at the boundary between water and oil droplets, reducing surface tension so they blend into a stable emulsion. This prevents the product from separating and gives a smooth, even texture when applied to skin.
Is Bis-Isobutyl PEG-13/Dimethicone Copolymer safe for most people?
Considered safe for cosmetic use at typical concentrations. Low irritation and comedogenic scores make it suitable for most skin types, including sensitive and acne-prone skin.
Who should be careful with Bis-Isobutyl PEG-13/Dimethicone Copolymer?
Those strictly avoiding all silicones or PEG compounds
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.