Ceteareth-20: 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: June 25, 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 Ceteareth-20?

Ceteareth-20 is a synthetic compound created by reacting cetyl and stearyl fatty alcohols (both derived from natural sources like coconut or palm oil) with roughly twenty units of ethylene oxide. The result is a waxy, white, water-soluble material that bridges the gap between oil and water, making it a versatile helper in countless personal care formulas.

The cosmetic industry began turning to ethoxylated fatty alcohols in the 1950s when formulators needed reliable, skin-friendly ingredients to improve texture and stability. Ceteareth-20 quickly gained popularity because it performed well at a reasonable cost and blended easily with a wide range of other raw materials.

Production starts with the purification of cetyl and stearyl alcohols extracted from plant oils. These alcohols undergo ethoxylation, where precise amounts of ethylene oxide attach to the fatty alcohol backbone. Careful temperature and pressure controls keep the reaction consistent, yielding an ingredient with the desired average of twenty ethylene oxide units.

You will most often spot Ceteareth-20 in creams, lotions, facial cleansers, makeup removers, sheet masks, tinted moisturizers, sunscreens, leave-in hair conditioners and styling creams. Its ability to keep formulas smooth and uniform allows brands to create lightweight hydrators just as easily as rich night creams.

Ceteareth-20’s Cosmetic Benefits/Uses

In a formula Ceteareth-20 pulls double duty, helping products look and feel better while keeping skin and hair fresh.

  • Cleansing: Its surface-active nature loosens dirt, excess oil and product buildup so they rinse away easily, which is why it often appears in face washes and micellar waters
  • Emulsifying: Ceteareth-20 binds water and oil phases into a stable emulsion, preventing separation and providing a smooth, uniform texture that spreads evenly on skin or hair

Who Can Use Ceteareth-20

Ceteareth-20 is generally well tolerated by normal, dry, combination and oily skin types thanks to its mild, non-occlusive nature. Highly sensitive or compromised skin may find it disruptive if the product also includes strong actives or fragrances, as its cleansing action can slightly weaken an already fragile barrier.

Because the cetyl and stearyl alcohols used to make Ceteareth-20 are most often sourced from coconut or palm oil, the finished material is suitable for vegans and vegetarians as long as a brand confirms plant origin on its supplier documents.

Current research shows no evidence that topical Ceteareth-20 poses a risk to pregnant or breastfeeding women. This is not medical advice and anyone who is pregnant or nursing should review personal care products with their doctor to be completely sure.

The ingredient is non-photosensitising, so it does not make skin more prone to sunburn. It is also fragrance free and non-volatile, meaning it will not exacerbate sun sensitivity that may already be present from other ingredients like retinoids.

Potential Side Effects/Adverse Reactions

Individual responses to Ceteareth-20 can vary. The points below outline potential side effects that could occur, though most people will not experience them when using a properly formulated product.

  • Mild skin irritation – rare stinging or redness, more likely on broken or highly sensitive skin
  • Allergic contact dermatitis – uncommon rash or itching in users with a specific sensitivity to ethoxylated compounds
  • Eye irritation – temporary tearing or discomfort if a cleanser containing the ingredient contacts the eyes
  • Dryness or tightness – possible if used in a high-foaming wash that strips natural oils
  • Contaminant concerns – trace 1,4-dioxane can remain if a manufacturer fails to properly purify the ingredient

If any discomfort, rash or persistent irritation occurs discontinue use and consult a healthcare professional.

Comedogenic Rating

Rating: 2 / 5

Ceteareth-20 contains fatty alcohol chains that can form a light film on skin, yet the added ethylene oxide units make it water soluble enough to rinse away without leaving a heavy residue. This balance places it on the lower end of the comedogenic scale rather than completely non-comedogenic.

Most people prone to acne or breakouts tolerate it well, but those who clog very easily may prefer to limit leave-on products that pair it with rich oils or butters.

Formulation matters: when used at modest levels in lightweight lotions or cleansers it is unlikely to cause congestion, whereas heavier creams with multiple occlusive ingredients could raise the clogging potential.

Summary

Ceteareth-20 acts as a cleansing agent and an emulsifier, meaning it can lift away dirt while binding oil and water into a stable, smooth mixture. Its partly-water-loving partly-oil-loving structure lets it sit at the interface of both phases, keeping formulas from separating and giving products a pleasant, even glide.

The ingredient remains popular with formulators thanks to its reliability, versatility and reasonable cost, so you will spot it in everything from face washes to leave-in hair products.

Current safety data shows it is non-sensitising for the vast majority of users, provided manufacturers properly remove trace 1,4-dioxane during purification. Still, skin can be unpredictable so it is smart to patch test any new product that includes Ceteareth-20 just to be sure it agrees with you.

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