Ingredient review

Aluminum Isostearates/Myristates

INCI: ALUMINUM ISOSTEARATES/MYRISTATES

A synthetic thickener and stabilizer that helps create smooth, creamy textures in makeup and skincare, but its aluminum content raises questions for some users.

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In plain English

Aluminum isostearates/myristates are man-made compounds that help give cosmetics a smooth, creamy feel. They work by thickening the product and keeping the oil and water parts from separating. Think of them like a gentle glue that holds the formula together so your foundation or lipstick doesn't turn watery or lumpy. The 'aluminum' part is a metal salt, but it's not the same as the aluminum used in antiperspirants—it's chemically different and used in tiny amounts to improve texture, not to stop sweat.

Quick decision guide

Useful, but context matters

Aluminum Isostearates/Myristates 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.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Aluminum Isostearates/Myristates.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. 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 aluminum salt of fatty acids (isostearic and myristic acids) used as a thickener and stabilizer in cosmetics.

How it works

It forms a network within the product that increases viscosity (thickness) and helps keep oil and water phases mixed together, preventing separation and improving the feel on skin.

Pros

Improves texture

Creates a smooth, creamy feel in products like lipsticks and foundations, making them easier to apply and more comfortable on skin.

Stabilizes formulas

Prevents oil and water from separating, so your product stays consistent from first use to last.

Cons and cautions

Aluminum concerns

Some people prefer to avoid aluminum in any form due to unconfirmed health worries, though cosmetic aluminum salts are considered safe by regulators.

No active benefit

It doesn't hydrate, soothe, or treat skin—it's purely a texture and stability ingredient.

Best for

  • Anyone using conventional makeup or skincare who wants a stable, smooth formula
  • People who prefer products with a creamy, non-greasy texture

Use caution if

  • Those who specifically avoid aluminum-based ingredients in cosmetics

Usage tips

Check the ingredient list if you prefer aluminum-free cosmetics
Use as part of a complete routine—this ingredient doesn't replace moisturizers or treatments

Safety summary

Considered safe for use in cosmetics at typical concentrations. The aluminum form used here is not absorbed through skin like some other aluminum compounds. Regulatory bodies like the Cosmetic Ingredient Review (CIR) have evaluated similar aluminum salts and found them safe.

Research notes

Limited direct studies on this specific compound, but the CIR has reviewed related aluminum fatty acid salts and concluded they are safe in cosmetics. No significant irritation or sensitization has been reported in patch tests.

Common label clues

Typical concentration
0.5% to 5%
Regulatory status
Approved for use in cosmetics by the FDA and EU CosIng database, with no specific restrictions at typical concentrations.
Common uses
Lipsticks, Foundations, Creams, Lotions, Eye shadows
Environmental note
Synthetic ingredient; not biodegradable in large quantities, but used in very small amounts per product.

Good to know

  • Aluminum isostearates/myristates are chemically different from aluminum chlorohydrate used in antiperspirants
  • Commonly found in lipsticks and cream eyeshadows for a smooth glide

Common questions

What is Aluminum Isostearates/Myristates in beauty products?

Aluminum isostearates/myristates are man-made compounds that help give cosmetics a smooth, creamy feel. They work by thickening the product and keeping the oil and water parts from separating. Think of them like a gentle glue that holds the formula together so your foundation or lipstick doesn't turn watery or lumpy. The 'aluminum' part is a metal salt, but it's not the same as the aluminum used in antiperspirants—it's chemically different and used in tiny amounts to improve texture, not to stop sweat.

What does Aluminum Isostearates/Myristates do in a beauty product?

It forms a network within the product that increases viscosity (thickness) and helps keep oil and water phases mixed together, preventing separation and improving the feel on skin.

Is Aluminum Isostearates/Myristates safe for most people?

Considered safe for use in cosmetics at typical concentrations. The aluminum form used here is not absorbed through skin like some other aluminum compounds. Regulatory bodies like the Cosmetic Ingredient Review (CIR) have evaluated similar aluminum salts and found them safe.

Who should be careful with Aluminum Isostearates/Myristates?

Those who specifically avoid aluminum-based ingredients in cosmetics

Research sources

Cosmetic Ingredient Review (CIR) - Aluminum Salts SafetyOpenEU CosIng DatabaseOpenFDA - Cosmetics IngredientsOpen

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.