Isostearyl Isostearate
Emollient ester · INCI: Isostearyl Isostearate
Reviewed by Elysiana Aguilar, master esthetician
How we read it
Known to clog pores. If you break out easily, this is the one to skip.
Is Isostearyl Isostearate comedogenic?
Yes. Isostearyl Isostearate is a known pore-clogging ingredient, and we read it as highly comedogenic. If you're acne-prone, it's worth avoiding, especially when it sits near the top of an ingredient list.
Why we read it this way
Isostearyl isostearate is a liquid ester in which both halves, the alcohol and the acid, are branched fatty chains, and it gives lip products, foundations and creams a cushioned slip. We read it as highly comedogenic, however elegant it feels.
The nuance
Diisostearyl malate shares the isostearyl name and sits in many of the same lip products, and we do not flag that one. With this ester, a foundation or face cream worn all day matters more than a lipstick.
Where it shows up
Lipsticks, lip glosses and balms use it for cushion and shine. It is also common in liquid foundations, pressed powders and rich moisturizers for dry skin.
Names we read the same way
- Isooctadecyl Isooctadecanoate
Related ingredients
One ingredient rarely tells the whole story. The acne ingredient checker reads everything in a product at once, the pore-clogging ingredients list has the rest of what we flag, and there is more on what comedogenic means. Also in the guides: What causes acne.