Magnesium Myreth Sulfate: 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
Share:
Inside this article:

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 Magnesium Myreth Sulfate?

Magnesium Myreth Sulfate is a synthetic ingredient made by joining a fatty alcohol derived from plant oils with ethylene oxide units then neutralizing the mix with magnesium. The result is a mild surfactant, which means it helps water and oil mix so dirt can be lifted away. Chemically it belongs to the family of sulfated ethoxylated alcohols and carries a magnesium salt that softens its feel on skin and hair.

First developed in the late 20th century as brands searched for gentler alternatives to traditional sulfates, it quickly found a place in everyday personal care items. Manufacturers create it in a controlled setting where the fatty alcohol is first reacted with ethylene oxide, sulfated, and finally treated with magnesium hydroxide to form the finished powder or paste.

You will most often see Magnesium Myreth Sulfate in shampoos, body washes, facial cleansers, bubble baths, liquid hand soaps and even some cleansing wipes. Its mild nature lets formulators build rich foam without the squeaky-dry afterfeel stronger sulfates can leave behind.

Magnesium Myreth Sulfate’s Cosmetic Benefits/Uses

In cosmetics Magnesium Myreth Sulfate serves one main role: cleansing. It lowers the surface tension of water so oils, sweat and daily grime loosen and rinse away more easily. A balanced charge from the magnesium counterion helps keep the surfactant gentle which makes it suitable for frequent use in products meant for sensitive skin and color-treated hair.

Who Can Use Magnesium Myreth Sulfate

Because it is a mild cleansing agent, Magnesium Myreth Sulfate is generally well tolerated by most skin types, including normal, oily, combination and even sensitive skin. Those with very dry or compromised skin should still watch for any tightness, as any surfactant can over-cleanse if used too often or left on too long.

The ingredient is produced from plant-derived fatty alcohols and synthetic processing steps that do not rely on animal by-products, so it is considered suitable for vegans and vegetarians. As always, check the finished product’s full ingredient list to confirm the brand’s overall cruelty-free and animal-free status.

No data suggest that Magnesium Myreth Sulfate poses a special risk during pregnancy or while breastfeeding when used topically in rinse-off products. Still, this is not medical advice and expectant or nursing women should run any skincare product past their doctor to be on the safe side.

The ingredient is not known to cause photosensitivity, so it does not make skin more prone to sunburn. It is also color-safe for treated hair and compatible with most other common cleansing agents.

Potential Side Effects/Adverse Reactions

Reactions to topical Magnesium Myreth Sulfate vary from person to person. The following list covers potential side effects, though most users will not experience them when the ingredient is properly formulated and used as directed.

• Mild eye irritation if the product accidentally contacts the eyes
• Temporary skin dryness or tightness, especially with frequent washing or very high concentrations
• Redness or stinging in individuals with extremely sensitive or compromised skin barriers
• Rare allergic contact dermatitis presenting as itching, rash or hives

If any unwanted reaction occurs, discontinue use and seek advice from a healthcare professional or dermatologist.

Comedogenic Rating

Rating: 0 (non-comedogenic)
Magnesium Myreth Sulfate is a fully water-soluble surfactant that rinses off cleanly without leaving oily residue in pores, so it does not promote blackheads or clogged follicles. Its molecular structure is too large and too polar to remain on skin long enough to cause blockage. This makes it suitable for people who are prone to acne or breakouts. Because it is usually used in rinse-off products, any transient contact with skin is minimal, further lowering comedogenic risk.

Summary

Magnesium Myreth Sulfate is a mild cleanser that lifts away oil, dirt and product buildup by lowering water’s surface tension and forming micelles that trap grime. The magnesium counterion softens its charge, giving it a gentler feel compared with traditional sulfates.

It appears in many mainstream shampoos, body washes and facial cleansers though it is not as famous as sodium laureth sulfate or newer sulfate-free blends. Brands choose it when they want solid foaming power with a softer touch.

Current safety data show it is low risk for irritation or allergy when used as directed in rinse-off formulas. Still, skin can be unpredictable so it is wise to patch test any new product containing this ingredient before full use.

Was this article helpful?
More from Glooshi:
ADVERTISEMENT
Get all our top headlines in beauty.
Delivered right to your inbox each week. Zero spam, all goodness, opt-out at anytime.
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Get the latest beauty news, top product recommendations & brand-exclusive discount codes direct to your inbox.
Send good feedback:

All feedback is greatly appreciated, anonymous, and will be used to improve the quality of our articles.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Send bad feedback:

All feedback is greatly appreciated, anonymous, and will be used to improve the quality of our articles.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Search