Ingredient review

PEG-5 Trimethylolpropane Trimyristate

INCI: PEG-5 TRIMETHYLOLPROPANE TRIMYRISTATE

A synthetic emollient that helps products feel silky and spread smoothly, with a low risk of irritation or clogged pores.

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In plain English

PEG-5 Trimethylolpropane Trimyristate is a man-made ingredient that acts like a lightweight oil. It helps creams and lotions glide onto your skin without feeling greasy or sticky. The 'PEG-5' part means it has been processed to be water-friendly, so it blends well in formulas. It's mostly used to improve the feel of a product, not to actively treat skin conditions.

Review score

Safety, usefulness, and evidence

3.8Good

3.8/ 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-5 Trimethylolpropane Trimyristate 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 PEG-5 Trimethylolpropane Trimyristate.
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

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 ester created by combining trimethylolpropane, myristic acid (a fatty acid from coconut or palm oil), and polyethylene glycol (PEG). It functions as an emollient and texture enhancer.

How it works

It sits on the surface of the skin, filling in tiny gaps between skin cells to create a smooth, soft feel. It also helps other ingredients spread evenly and reduces the 'drag' when applying products.

Pros

Silky, non-greasy feel

Unlike heavier oils, this ingredient provides a smooth, velvety texture that doesn't leave a sticky or oily residue, making it ideal for daytime wear.

Low irritation risk

It has a very low potential to cause redness or stinging, even on sensitive skin, because it's a large molecule that doesn't penetrate deeply.

Cons and cautions

Synthetic production

It is made in a lab from petrochemicals and natural fatty acids, which may not align with preferences for naturally derived or minimal-ingredient routines.

PEG purity concerns

PEG compounds can sometimes contain trace impurities like ethylene oxide or 1,4-dioxane if not properly purified, though reputable brands test for these.

Best for

Anyone who wants a lightweight, non-greasy moisturizer or makeup
People with oily or combination skin looking for a silky finish without heaviness

Use caution if

Those who strictly avoid synthetic or PEG-based ingredients for personal or environmental reasons

Usage tips

Look for this ingredient in the middle to bottom of the ingredient list — it's used in small amounts for texture, not as a primary moisturizer.

Pair with a water-based serum if you have oily skin, as this emollient works well under makeup without causing shine.

Safety summary

PEG-5 Trimethylolpropane Trimyristate is considered safe for use in cosmetics at typical concentrations. The Cosmetic Ingredient Review (CIR) panel has reviewed similar PEG esters and found them safe when formulated to meet purity standards. The main concern is potential contamination during manufacturing, which is tightly regulated in most countries.

Research notes

There are no specific peer-reviewed studies on this exact ingredient, but it belongs to a well-studied class of PEG esters. The CIR has reviewed many PEG compounds and concluded they are safe for cosmetic use when free of impurities. Industry data supports its low irritation and comedogenicity.

Common label clues

Typical concentration: 0.5% to 5%
Regulatory status: Approved for use in cosmetics by the FDA (USA) and the European Commission. No concentration restrictions in leave-on or rinse-off products.
Common uses: Moisturizers, Foundations, Lipsticks, Sunscreens
Environmental note: Synthetically produced, but the myristic acid portion is often derived from plant sources like coconut or palm oil. PEG components are biodegradable in water treatment systems.

Good to know

This ingredient is often used in lipsticks and foundations to improve glide and prevent caking.
It is considered biodegradable and not a known environmental hazard in typical cosmetic concentrations.

Common questions

What is PEG-5 Trimethylolpropane Trimyristate in beauty products?

What does PEG-5 Trimethylolpropane Trimyristate do in a beauty product?

It sits on the surface of the skin, filling in tiny gaps between skin cells to create a smooth, soft feel. It also helps other ingredients spread evenly and reduces the 'drag' when applying products.

Is PEG-5 Trimethylolpropane Trimyristate safe for most people?

Who should be careful with PEG-5 Trimethylolpropane Trimyristate?

Those who strictly avoid synthetic or PEG-based ingredients for personal or environmental reasons

Research sources

Cosmetic Ingredient Review (CIR) – Safety of PEGsOpen European Commission CosIng DatabaseOpen PubChem – PEG-5 Trimethylolpropane TrimyristateOpen

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.