Ingredient review

Bis-PPG-7 Undeceneth-21 Dimethicone

INCI: BIS(PPG-7 UNDECENETH-21) DIMETHICONE

A gentle silicone emulsifier that improves product texture and stability without clogging pores.

beautyskincareemulsifier

In plain English

This is a silicone-based ingredient that helps water and oil mix together in creams and lotions. It also makes products feel silky and smooth on your skin, without leaving a greasy residue. Because it's a large molecule, it mostly sits on the surface of your skin, so it's unlikely to cause breakouts or irritation.

Review score

Safety, usefulness, and evidence

4.0Good
4.0/ 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
synthetic
Evidence
moderate
Irritation
low
Clogging risk
low
How reviews are scored

Quick decision guide

Useful, but context matters

Bis-PPG-7 Undeceneth-21 Dimethicone 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 Bis-PPG-7 Undeceneth-21 Dimethicone.
  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

A synthetic silicone polymer modified with PPG (polypropylene glycol) and undeceneth chains to act as a water-in-oil or oil-in-water emulsifier. It is part of the dimethicone family, known for its smooth, non-greasy feel.

How it works

It reduces the surface tension between water and oil droplets, allowing them to form a stable, uniform mixture. In a formula, it helps create a lightweight, spreadable texture and leaves a soft, velvety film on the skin that can also help other ingredients adhere better.

Pros

Excellent texture enhancer

Creates a silky, smooth feel on skin that helps makeup apply evenly and reduces the greasy sensation of oils.

Low irritation and comedogenic risk

Large molecular size means it stays on the skin's surface, making it unlikely to clog pores or cause breakouts, even for sensitive skin.

Cons and cautions

Synthetic origin

As a lab-made silicone, it may not be preferred by those seeking natural or minimal-ingredient routines.

Can feel heavy in high amounts

In formulas with a high concentration of this ingredient, some users may experience a slightly tacky or overly slick sensation.

Best for

  • People with normal to oily skin who prefer a matte finish
  • Those looking for a stable, long-lasting moisturizer or foundation

Use caution if

  • Individuals strictly avoiding all silicones in their routine

Usage tips

Apply to damp skin to help the emulsifier spread more evenly.
Use after water-based serums and before heavier creams or oils for best layering.
If you're sensitive to silicones, patch test a product containing this ingredient first.

Safety summary

Considered safe for cosmetic use at typical concentrations. Large molecular size limits skin penetration, reducing irritation and comedogenic risk. No significant safety concerns reported in regulatory reviews.

Research notes

Safety assessments by the Cosmetic Ingredient Review (CIR) panel have concluded that dimethicone and its derivatives are safe as used in cosmetics. Specific studies on this modified silicone are limited, but its structure suggests low bioavailability and low toxicity.

Common label clues

Typical concentration
0.5% to 5%
Regulatory status
Approved for use in cosmetics globally, including by the U.S. FDA and EU CosIng database, with no known restrictions at typical use levels.
Common uses
Moisturizers, Sunscreens, Foundations, Primers, Serums
Environmental note
Silicones can persist in the environment; however, this modified silicone is designed to be more biodegradable than traditional dimethicones.

Good to know

  • This ingredient is often used in 'water-resistant' sunscreens because it helps the formula stay intact on skin.
  • It is biodegradable under certain conditions, though its environmental fate is still being studied.

Common questions

What is Bis-PPG-7 Undeceneth-21 Dimethicone in beauty products?

This is a silicone-based ingredient that helps water and oil mix together in creams and lotions. It also makes products feel silky and smooth on your skin, without leaving a greasy residue. Because it's a large molecule, it mostly sits on the surface of your skin, so it's unlikely to cause breakouts or irritation.

What does Bis-PPG-7 Undeceneth-21 Dimethicone do in a beauty product?

It reduces the surface tension between water and oil droplets, allowing them to form a stable, uniform mixture. In a formula, it helps create a lightweight, spreadable texture and leaves a soft, velvety film on the skin that can also help other ingredients adhere better.

Is Bis-PPG-7 Undeceneth-21 Dimethicone safe for most people?

Considered safe for cosmetic use at typical concentrations. Large molecular size limits skin penetration, reducing irritation and comedogenic risk. No significant safety concerns reported in regulatory reviews.

Who should be careful with Bis-PPG-7 Undeceneth-21 Dimethicone?

Individuals strictly avoiding all silicones in their routine

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.