Peg-8 Myristate: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: July 1, 2025
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We verify all information on this page using publicly available nomenclature standards from The Personal Care Products Council (PCPC), the European Commission's CosIng database and documentation provided directly by ingredient manufacturers. Our analysis is based on technical data from these sources to ensure accuracy and reliability.

What Is Peg-8 Myristate?

Peg-8 Myristate is a synthetic ingredient created by reacting myristic acid, a fatty acid originally found in coconut and nutmeg oils, with eight units of ethylene oxide. This process attaches small water-loving portions to an oil-like chain, giving the molecule both oily and watery sides. Chemists began exploring these hybrid molecules in the mid-20th century to help mix oil and water in creams and lotions, and Peg-8 Myristate soon became a favorite for its mildness and versatility. Today manufacturers produce it in controlled factory settings where purified myristic acid is combined with measured amounts of ethylene oxide under heat and pressure, then carefully purified to remove residues. You will most often see Peg-8 Myristate in lightweight facial moisturizers, cleansing milks, sheet masks, soothing after-sun gels, hair conditioners and even some color cosmetics where a smooth, non-greasy feel is important.

Peg-8 Myristate’s Cosmetic Benefits/Uses

In skin and hair care formulas Peg-8 Myristate serves a single, yet essential, role.

As an emulsifying agent it helps oil and water blend evenly so the product stays smooth from the first use to the last. This stable mix means creams do not separate in the jar, serums feel light instead of greasy and cleansing products rinse away without leaving a heavy film.

Who Can Use Peg-8 Myristate

Peg-8 Myristate is considered gentle enough for most skin types including dry, normal, combination, oily and even many sensitive skins because it has a light silky texture and a low likelihood of clogging pores. People with extremely reactive or compromised skin should still scan ingredient lists for other possible triggers in the formula, as Peg-8 Myristate itself rarely causes trouble.

The ingredient is produced from plant derived myristic acid and petrochemically sourced ethylene oxide, so it does not rely on animal byproducts. This makes it acceptable for vegans and vegetarians provided the finished product is certified cruelty free.

Current safety data indicate no specific risks for pregnant or breastfeeding women when Peg-8 Myristate is used topically at the levels found in cosmetics. That said this is not medical advice and anyone who is expecting or nursing should review their skincare routine with a qualified healthcare provider.

Peg-8 Myristate does not absorb UV light or make the skin more sensitive to the sun, so it is not linked to photosensitivity. It also works well across a wide pH range and is odorless, which helps minimize additional irritation triggers.

Potential Side Effects/Adverse Reactions

Reactions to topical Peg-8 Myristate differ from person to person. The points below outline potential side effects though most consumers will not experience them when using a properly formulated product.

  • Mild skin irritation – a temporary stinging or itching sensation in very sensitive individuals
  • Redness or flushing – usually short lived and often linked to other active ingredients in the same product
  • Contact dermatitis – rare allergic response that may present as patches of rash or swelling
  • Eye irritation – watering or discomfort if the ingredient enters the eyes, most common with cleansers
  • Increased penetration of other actives – by helping ingredients mix and spread it can slightly boost how quickly certain actives reach deeper layers which could intensify their effects on delicate skin

If you notice any persistent discomfort discontinue use and seek advice from a pharmacist or healthcare professional.

Comedogenic Rating

Rating: 1 / 5

Peg-8 Myristate carries a very low risk of clogging pores because the polyethylene glycol (PEG) portion makes the fatty myristate chain water soluble which helps it rinse away easily. Unlike highly occlusive myristate esters such as isopropyl myristate, this PEGylated version leaves only a light film that is unlikely to trap sebum or dead skin cells. Therefore it is generally suitable for acne-prone or breakout-prone skin, though individual reactions can vary.

Because the molecule is small and partly water loving, it does not linger in follicles the way heavier oils do. Still, products that pair Peg-8 Myristate with richer butters or waxes could raise overall pore-clogging potential so always consider the full ingredient list.

Summary

Peg-8 Myristate is primarily an emulsifier that keeps oil and water blended so lotions, serums and cleansers stay smooth and pleasant to use. It achieves this by combining an oil-like myristate tail with a water-loving PEG head which positions itself between the two phases and prevents separation. This same property also gives finished products a lighter, less greasy feel that rinses cleanly.

While not the most buzzworthy name in beauty, Peg-8 Myristate remains a quiet workhorse found in everyday moisturizers, gentle cleansers and soothing after-suns where stability and skin comfort matter more than marketing appeal.

Safety reviews show it is well tolerated across skin types with only rare reports of irritation. As with any new cosmetic ingredient it is smart to perform a small patch test when trying a fresh product just to be sure your skin agrees.

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