Isostearyl isostearate: is it comedogenic? What it does in skincare

What it does

Heavy, cushiony emollient that softens dry skin.

• Binding
• Emollient
• Skin conditioning

Isostearyl isostearate in plain English

Isostearyl isostearate is a thick, rich ester that gives balms, lipsticks and heavy creams a cushiony feel. It rates high on classic comedogenic lists, so acne-prone skin may want to avoid it in leave-on face products. Its rating comes from old rabbit-ear tests of the raw ingredient, which can overstate what happens with a finished product on human skin.

Is isostearyl isostearate bad for acne?

It can be. Isostearyl isostearate has a high clog risk rating for acne-prone skin. In Fulton's 1989 rabbit-ear test it scored 4 out of 5 for clogging pores and 1 out of 5 for irritation. That test used the raw ingredient, so a small amount in a finished product may behave differently. If you break out easily, check where it sits on the ingredient list: the higher it appears, the more of it the product usually contains.

Why it is flagged: A heavy emollient ester that rates high on classic comedogenic lists.

Clean routine and still breaking out? The cause may be internal. See what is driving it

Also called

• Isostearyl Isostearate

Related ingredients

• Isopropyl isostearateHigh clog riskSilky emollient ester that softens skin
• Isopropyl lanolateModerate clog riskRich lanolin-based emollient that softens and protects
• Isopropyl linoleateHigh clog riskEmollient ester that softens and conditions skin
• Isopropyl stearateModerate clog riskEmollient ester that softens skin and adds slip
• Isostearyl neopentanoateHigh clog riskSilky emollient ester common in makeup and lip products
• Acetylated lanolin alcoholHigh clog riskLight lanolin-based emollient that softens skin