Ingredient review

PEG-90 Polycaprolactone

INCI: PEG-90/POLYEPSILON CAPROLACTONE

A synthetic polymer that helps products spread smoothly and form a light, flexible film on skin, but offers no direct active benefits.

beautyskincarefilm-former

In plain English

This ingredient is a man-made polymer—a long chain of repeating molecules—that helps skincare products feel silky and spread easily. When applied, it dries into a thin, flexible film on your skin, which can help other ingredients stay put or give a temporary smoothing effect. It doesn't actively treat skin concerns like dryness or aging; it's more of a texture and performance helper.

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

PEG-90 Polycaprolactone 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-90 Polycaprolactone.
  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-90/Polyepsilon Caprolactone is a synthetic polymer created by combining polyethylene glycol (PEG) with polycaprolactone, a biodegradable polyester. It is designed to improve the feel and application of cosmetic products.

How it works

In a formula, this ingredient dissolves in water or oil and then, as the product dries on the skin, it forms a continuous, flexible film. This film can lock in other ingredients, reduce water loss temporarily, and give a smooth, non-sticky finish. It also thickens the product, making it easier to apply evenly.

Pros

Improves product feel

Helps creams and serums glide on smoothly without a sticky or heavy sensation, making your routine more pleasant.

Flexible film

Forms a light, breathable layer that can help other ingredients stay on your skin longer without feeling tight or stiff.

Cons and cautions

No active benefits

This ingredient doesn't hydrate, exfoliate, or treat skin concerns—it's purely a texture enhancer, so it won't improve your skin on its own.

Synthetic origin

Made from petrochemicals, it may not align with preferences for natural or biodegradable ingredients, though polycaprolactone is biodegradable.

Best for

  • Anyone who wants a smoother, more elegant product texture
  • People using sheet masks or leave-on treatments that benefit from a film-forming ingredient

Use caution if

  • Those seeking purely natural or plant-based skincare
  • Individuals with very sensitive skin who prefer minimal ingredient lists

Usage tips

Use products with this ingredient as the last step in your routine to maximize the film-forming effect.
If you notice a slight tackiness, apply a very thin layer—less is more with film-forming polymers.

Safety summary

PEG-90/Polyepsilon Caprolactone is considered safe for cosmetic use at typical concentrations. It has low irritation and comedogenic potential. However, as with all PEG derivatives, purity is important to avoid contamination with potentially harmful byproducts. Regulatory bodies have not flagged significant safety concerns.

Research notes

Research on this specific polymer is limited, but polycaprolactone is well-studied in biomedical applications as a safe, biodegradable material. In cosmetics, its role is primarily functional, and no peer-reviewed studies indicate significant skin benefits or risks beyond those typical of film-forming agents.

Common label clues

Typical concentration
0.5% to 5%
Regulatory status
Approved for use in cosmetics in the US, EU, and many other regions. The EU CosIng database lists PEG-90/Polyepsilon Caprolactone as a film-forming agent with no specific restrictions at typical use levels.
Common uses
Masks, Serums, Moisturizers, Sunscreens
Environmental note
Polycaprolactone is biodegradable under industrial composting conditions, but PEG components may persist longer. Overall, it has a lower environmental impact than many non-biodegradable synthetic polymers.

Good to know

  • Polycaprolactone is a biodegradable polyester, so this ingredient is more environmentally friendly than some other synthetic polymers.
  • PEG compounds can be contaminated with ethylene oxide during manufacturing, but reputable brands use purified grades that are safe for cosmetic use.

Common questions

What is PEG-90 Polycaprolactone in beauty products?

This ingredient is a man-made polymer—a long chain of repeating molecules—that helps skincare products feel silky and spread easily. When applied, it dries into a thin, flexible film on your skin, which can help other ingredients stay put or give a temporary smoothing effect. It doesn't actively treat skin concerns like dryness or aging; it's more of a texture and performance helper.

What does PEG-90 Polycaprolactone do in a beauty product?

In a formula, this ingredient dissolves in water or oil and then, as the product dries on the skin, it forms a continuous, flexible film. This film can lock in other ingredients, reduce water loss temporarily, and give a smooth, non-sticky finish. It also thickens the product, making it easier to apply evenly.

Is PEG-90 Polycaprolactone safe for most people?

PEG-90/Polyepsilon Caprolactone is considered safe for cosmetic use at typical concentrations. It has low irritation and comedogenic potential. However, as with all PEG derivatives, purity is important to avoid contamination with potentially harmful byproducts. Regulatory bodies have not flagged significant safety concerns.

Who should be careful with PEG-90 Polycaprolactone?

Those seeking purely natural or plant-based skincare Individuals with very sensitive skin who prefer minimal ingredient lists

Research sources

CosIng - PEG-90/Polyepsilon CaprolactoneOpenPubMed - Polycaprolactone in biomedical applicationsOpenEWG Skin Deep - PEG-90/Polyepsilon CaprolactoneOpen

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.