Ingredient review

PEI-1500

INCI: PEI-1500

PEI-1500 is a synthetic polymer that helps products spread smoothly and stay put, but it's not a star ingredient for skin health.

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In plain English

PEI-1500 is a man-made ingredient that acts like a glue or coating in cosmetics. It helps other ingredients stick to your skin or hair, and it can make a product feel smoother or more spreadable. Think of it as a helper that improves the texture and staying power of things like mascara or hair gel, but it doesn't actively moisturize or treat your skin.

Review score

Safety, usefulness, and evidence

3.5Good
3.5/ 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

PEI-1500 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 PEI-1500.
  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

PEI-1500 is a specific molecular weight version of polyethylenimine, a synthetic polymer made from repeating units of ethyleneimine. In cosmetics, it's used primarily for its film-forming and binding properties.

How it works

When applied, PEI-1500 forms a thin, flexible film on the skin or hair surface. This film helps other ingredients adhere better, improves water resistance, and can give a smooth, even feel. It also acts as a binder, holding pressed powders or pigments together.

Pros

Improves product performance

PEI-1500 helps makeup and hair products last longer and feel smoother, so you get better wear without extra effort.

Low irritation potential

At typical use levels, PEI-1500 is considered very low risk for skin irritation or clogging pores, making it suitable for most skin types.

Cons and cautions

Synthetic and non-biodegradable

As a synthetic polymer, PEI-1500 is not biodegradable and may raise environmental concerns for eco-conscious users.

Limited skin benefit

PEI-1500 is a functional ingredient that improves texture and wear, but it doesn't provide active skincare benefits like hydration or antioxidant protection.

Best for

  • Anyone using long-wear makeup or styling products
  • People who want a smooth, non-tacky finish

Use caution if

  • Those strictly avoiding all synthetic ingredients
  • Individuals with known sensitivity to polymers (rare)

Usage tips

Use in small amounts—more isn't better and can cause a tacky feel.
Pair with humectants like glycerin if you want both hold and hydration.

Safety summary

PEI-1500 is considered safe for cosmetic use at typical concentrations. It has low irritation and comedogenic potential, but long-term or high-exposure data is limited. Always patch test new products.

Research notes

Research on PEI-1500 in cosmetics is limited. Most safety data comes from general polymer studies and industry assessments. It is not associated with significant toxicity in topical use, but more independent studies would be valuable.

Common label clues

Typical concentration
0.1% to 2%
Regulatory status
Approved for use in cosmetics in the US, EU, and many other regions, subject to concentration limits and purity standards.
Common uses
Hair styling products, Mascara, Eyeliners, Skin lotions
Environmental note
PEI-1500 is a synthetic polymer and not readily biodegradable. Its environmental impact is a consideration for brands focusing on sustainability.

Good to know

  • PEI-1500 is different from PEI used in medical or industrial contexts; cosmetic-grade is purified for safety.
  • It's often found in 'waterproof' or 'long-wear' formulas.

Common questions

What is PEI-1500 in beauty products?

PEI-1500 is a man-made ingredient that acts like a glue or coating in cosmetics. It helps other ingredients stick to your skin or hair, and it can make a product feel smoother or more spreadable. Think of it as a helper that improves the texture and staying power of things like mascara or hair gel, but it doesn't actively moisturize or treat your skin.

What does PEI-1500 do in a beauty product?

When applied, PEI-1500 forms a thin, flexible film on the skin or hair surface. This film helps other ingredients adhere better, improves water resistance, and can give a smooth, even feel. It also acts as a binder, holding pressed powders or pigments together.

Is PEI-1500 safe for most people?

PEI-1500 is considered safe for cosmetic use at typical concentrations. It has low irritation and comedogenic potential, but long-term or high-exposure data is limited. Always patch test new products.

Who should be careful with PEI-1500?

Those strictly avoiding all synthetic ingredients Individuals with known sensitivity to polymers (rare)

Research sources

Cosmetic Ingredient Review (CIR) - Polyethylenimine SafetyOpenPubChem - Polyethylenimine 1500OpenEuropean Chemicals Agency (ECHA) - PolyethylenimineOpen

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.