Ingredient dictionary

Polyglyceryl-4 Isostearate

A gentle emulsifier made from glycerin and isostearic acid, which helps oil and water blend into one smooth cream. It is on the label of 14 products in our library. Checked against our library November 6, 2026.

What Polyglyceryl-4 Isostearate does

Keeps oil and water blended
Adds a soft, cushiony feel
Supports an even, stable texture

Polyglyceryl-4 Isostearate is made by linking several glycerin units to isostearic acid, a branched form of stearic acid found in plant and animal fats. The result is a nonionic ester, which means it carries no electric charge and tends to be gentle and easy to combine with other ingredients.

Formulators use it because it helps water and oil stay mixed, so a cream stays smooth in the jar rather than separating. Its branched chain tends to leave a soft, cushiony feel instead of a heavy film. You will often see it in moisturizers and sunscreens, where an even, comfortable spread matters.

Good for

Suits moisturizers and sunscreens, especially formulas that need a silky, stable texture.

Frequently asked questions

Is Polyglyceryl-4 Isostearate good for sensitive skin?

It is generally well tolerated since it is a mild, nonionic emulsifier. Any ingredient can still bother a particular person, so patch testing a new product on a small area first is a sensible habit. A dermatologist can help if you have concerns.

Is Polyglyceryl-4 Isostearate vegan?

It depends on where the glycerin and fatty acid come from. Both can be plant-based or synthetic, so the answer varies by brand and batch. Check the product's own label or contact the maker for sourcing details.