What Is Aluminum Isostearates/Myristates?
Aluminum Isostearates/Myristates is a cosmetic ingredient made by reacting aluminum with two fatty acids found in plants and animal oils: isostearic acid and myristic acid. The result is a soft powdered salt that blends well with both oils and water, making it handy for many beauty formulas. Chemists first experimented with aluminum salts in the mid-1900s to improve the texture of makeup and soon discovered that pairing aluminum with these specific fatty acids created a stable, skin-friendly material. Today manufacturers produce it in controlled reactors where purified fatty acids meet an aluminum compound, then the mixture is filtered, dried and milled into a fine powder.
You will most often see Aluminum Isostearates/Myristates in pressed powders, liquid foundations, sunscreens, cream blushes, lipsticks, antiperspirant sticks, mask formulas and certain anti-aging or soothing moisturizers that need a smooth, non-greasy feel.
Aluminum Isostearates/Myristates’s Cosmetic Benefits/Uses
This multitasking powder supports both the look and shelf life of many personal care products.
- Anticaking: Keeps powder particles from clumping so pressed or loose makeup stays silky and easy to apply
- Emulsion stabilising: Helps oil and water stay evenly mixed which stops creams or lotions from separating while sitting on the bathroom shelf
- Opacifying: Adds controlled whiteness that hides imperfections in a formula, giving foundations or sunscreens better coverage and a uniform color
- Viscosity controlling: Adjusts thickness so a product feels just right whether it is a light lotion or a rich cream
Who Can Use Aluminum Isostearates/Myristates
This ingredient is generally well tolerated by most skin types including normal, dry, oily and combination skin because it sits on the surface rather than penetrating deeply. Sensitive skin users also tend to do fine with it since it has a low irritation profile, although anyone with a known allergy to aluminum salts should proceed cautiously. Acne-prone skin usually handles it without issue as its comedogenic rating is low, yet very congestible skin may prefer lighter formulas.
Aluminum Isostearates/Myristates can be vegan friendly when the fatty acids come from plant oils, but some manufacturers still rely on animal-derived sources. Shoppers who follow vegan or vegetarian lifestyles should look for products that state “vegetable derived” or carry a suitable certification.
No evidence shows that topical use poses a risk for people who are pregnant or breastfeeding. Still, this is not medical advice and anyone expecting or nursing should run their skincare choices past a qualified healthcare professional.
The compound does not increase photosensitivity so you do not need special sun precautions beyond your usual daily sunscreen.
Potential Side Effects/Adverse Reactions
Responses to any cosmetic ingredient differ from person to person. The points below note potential side effects of Aluminum Isostearates/Myristates though most users will not experience them when the product is formulated and used correctly.
- Mild skin irritation
- Redness or itching in individuals sensitive to aluminum salts
- Clogged pores in very acne-prone skin if the overall formula is heavy
- Contact dermatitis in rare cases of specific fatty acid allergy
If you notice any unexpected discomfort or reaction stop using the product and consult a healthcare professional.
Comedogenic Rating
Rating: 1 / 5
Aluminum Isostearates/Myristates sits mostly on the skin surface, has a powdery texture and does not form a heavy, greasy film. These traits keep it from blocking pores the way thicker oils or waxes can. A few people with very congestion-prone skin might still react if the overall formula is rich but the ingredient itself is classed as low risk.
In short, it is generally fine for acne-prone users.
Summary
Aluminum Isostearates/Myristates stabilises emulsions, stops powders from caking, controls thickness and adds gentle opacity that helps products look smooth and even. It does this by dispersing evenly through both oil and water phases, coating pigment particles and creating a light network that thickens without greasiness.
You will see it in a steady range of makeup and skincare but it is not a trendy spotlight ingredient so most shoppers never notice it on the label. Chemists like it because it quietly boosts texture and shelf life.
Current data shows it is safe for topical use with a very low irritation profile. Still, skin can be unpredictable so it is smart to patch test any new product that lists this ingredient.