Sodium Myristoyl Isethionate: 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 30, 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 Sodium Myristoyl Isethionate?

Sodium Myristoyl Isethionate is a mild surfactant created by combining myristic acid, a fatty acid most often sourced from coconut or palm kernel oil, with isethionic acid then neutralizing the mix with sodium. The result is a white, powdery or flake-like ingredient that dissolves easily in water and produces a rich, creamy lather. First introduced in the 1950s as an alternative to the harsher soaps of the time, it quickly found favor because it cleans without stripping skin or hair of natural oils. Today manufacturers produce it through controlled esterification followed by sulfonation, a process that allows for high purity and consistent performance. You will spot it in sulfate free shampoos, conditioning cleansers, facial washes, body washes, baby cleansers, syndet (synthetic detergent) bars and even some shaving creams and foaming face masks.

Sodium Myristoyl Isethionate’s Cosmetic Benefits/Uses

Formulators value this ingredient for several helpful roles

  • Cleansing: Lifts away dirt, oil and product buildup while being gentle enough for sensitive skin or daily use
  • Foaming: Creates a dense, luxurious foam that improves spreadability and gives users the satisfying feel of a thorough wash
  • Hair conditioning: Deposits a light, soft feel on hair strands helping them stay smooth and manageable after rinsing
  • Antistatic: Reduces static charge on hair which helps cut down on flyaways and frizz

Who Can Use Sodium Myristoyl Isethionate

Thanks to its mild nature Sodium Myristoyl Isethionate is generally well tolerated by all skin types including sensitive dry combination and oily. Those with very reactive or allergy-prone skin should still scan ingredient lists for potential triggers but the molecule itself is not known to aggravate common conditions like eczema or rosacea.

The ingredient is usually produced from coconut or palm kernel oil so it is suitable for vegans and vegetarians. If ethical sourcing of palm oil is a concern look for brands that certify sustainable supply chains.

Current safety data show no issues for women who are pregnant or breastfeeding when using products that contain Sodium Myristoyl Isethionate. This is not medical advice and anyone who is expecting or nursing should review their personal care routine with a healthcare professional to be certain it meets their individual needs.

Sodium Myristoyl Isethionate does not increase skin sensitivity to sunlight and has no known interactions with common topical actives used in routine skincare.

Potential Side Effects/Adverse Reactions

Responses to any cosmetic ingredient can differ from person to person. The points below outline potential side effects yet most users experience none of them when the finished product has been properly formulated.

  • Mild skin irritation such as redness or itching, typically in those with existing sensitivities
  • Eye irritation if the product accidentally gets into the eyes
  • Allergic contact dermatitis in rare cases where an individual is specifically allergic to coconut or palm derivatives
  • Temporary dryness or tightness if the formula contains a high concentration and is used repeatedly without follow-up moisturization

If any uncomfortable reaction occurs stop using the product immediately and consult a healthcare professional for guidance.

Comedogenic Rating

Rating: 1 out of 5

Sodium Myristoyl Isethionate is a water-soluble surfactant that rinses away cleanly and does not leave an oily film on skin so it has very little tendency to clog pores. Its fatty acid chain is balanced by the highly soluble isethionate portion which keeps residue from building up inside follicles.

Because of this low rating it is generally suitable for people who are prone to acne or breakouts.

Finished formulas that pair it with heavy oils or waxes could raise the overall comedogenic potential so the whole ingredient list still matters.

Summary

Sodium Myristoyl Isethionate cleanses by lowering the surface tension of water allowing dirt and oil to lift away easily. It foams richly which helps spread the product across skin or hair and it leaves a light conditioning film that reduces static and keeps strands smooth. These benefits make it popular in sulfate free shampoos, gentle facial cleansers, body washes and syndet bars.

The ingredient enjoys steady popularity because it offers a kinder alternative to traditional sulfates yet still gives that satisfying lather most users expect. Safety assessments rate it as low risk for irritation or sensitization when used as directed.

Overall it is considered safe for routine use, but as with any new cosmetic ingredient it is wise to patch test a product first to ensure personal compatibility.

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