What Is Aluminum Starch Octenylsuccinate?
Aluminum starch octenylsuccinate is a modified plant starch that has been bonded with octenyl succinic anhydride and then treated with a small amount of aluminum salt. Most manufacturers start with corn or potato starch, giving the ingredient a naturally derived base before it is chemically adapted to perform better in modern cosmetics. This modification was first explored in the late 1980s as brands looked for plant based alternatives to talc that could still control oil and improve texture. By the mid-1990s the ingredient had found a steady place in color cosmetics and skin care, and today it is a staple in many oil-absorbing or mattifying formulas.
The production process involves two main steps. First, raw starch granules react with octenyl succinic anhydride, which links to the starch molecules and adds a light hydrophobic character. Next, the treated starch is combined with a food-grade aluminum salt that helps stabilize the new structure and enhances its oil binding properties. The final powder is fine, silky and able to disperse well in both water-based and oil-based systems.
You will most often see aluminum starch octenylsuccinate in loose and pressed face powders, liquid and powder foundations, primers, tinted moisturizers, sunscreens, dry shampoos, deodorant sticks, clay or cream masks and even some lightweight lotions where a matte finish is desired.
Aluminum Starch Octenylsuccinate’s Cosmetic Benefits/Uses
This multitasking powder improves the feel and performance of many everyday products
- Absorbent – soaks up excess sebum and sweat which cuts down on midday shine leaves skin looking matte and helps makeup last longer
- Anticaking – keeps loose or pressed powders from clumping ensures the product stays free flowing and easy to apply while also preventing the formation of hard spots in compacts
- Viscosity Controlling – lightly thickens watery formulas giving creams lotions and sprays a smoother consistency that spreads evenly without feeling heavy or sticky
Who Can Use Aluminum Starch Octenylsuccinate
This powder is gentle enough for most skin types. It shines on oily and combination skin because it absorbs excess oil and keeps shine down. Normal skin can also benefit from its smoothing feel. Very dry skin may find it a little too oil absorbing if used in high amounts but it is rarely a deal breaker when blended into a cream or lotion.
The ingredient comes from plant starch and the small amount of aluminum salt is mineral based, so it is suitable for vegans and vegetarians.
Current data shows no specific risk for pregnant or breastfeeding women when the ingredient is used topically in cosmetics. That said this is not medical advice and anyone who is expecting or nursing should check with a healthcare provider before adding new products, just to be safe.
Aluminum starch octenylsuccinate does not cause photosensitivity and there are no special sun care rules that come with it.
Potential Side Effects/Adverse Reactions
Reactions to any cosmetic ingredient can vary from person to person. The points below cover potential side effects but most people will not notice any problems when the ingredient is used at normal levels in well made products.
- Mild skin irritation such as redness or itching in sensitive users
- Dryness or tightness if used in high concentration on already dry skin
- Rare allergic contact dermatitis for those with a starch or aluminum sensitivity
- Minor respiratory irritation if large amounts of loose powder are inhaled during application
If you notice any of these issues stop using the product and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 1 / 5
Aluminum starch octenylsuccinate is considered low on the pore-clogging scale because it is a lightweight powder that sits on the surface of the skin, binds oil and moisture rather than acting like an occlusive film and has no oily or waxy components that typically trigger breakouts. Its large particle size keeps it from penetrating into pores and the small amount of aluminum salt does not alter this behavior.
Suitable for acne-prone or breakout-prone skin in most cases.
People who find any starches problematic may want to monitor their skin, but reports of clogged pores from this specific ingredient are uncommon.
Summary
Aluminum starch octenylsuccinate serves as an absorbent, anticaking and viscosity controlling agent. It performs these roles by soaking up excess oil and sweat, keeping powders free flowing, preventing hard spots in pressed products and adding a touch of thickness to watery formulas so they apply smoothly without heaviness.
The ingredient is widely used in mattifying primers, foundations, face powders, sunscreens, dry shampoos and deodorants, making it a familiar name for anyone who shops for shine-control products. Its plant-based origin backed by decades of safe cosmetic use has helped it maintain steady popularity across both drugstore and prestige brands.
Current research shows it has a low risk profile with minimal likelihood of irritation or pore clogging for most users. As with any new skincare or makeup item it is smart to perform a quick patch test when trying a product that contains aluminum starch octenylsuccinate to be sure it agrees with your individual skin.