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Polyglyceryl-4 Isostearate

What Polyglyceryl-4 Isostearate is & what it does

A mild, plant-derived emulsifier that blends oil and water and disperses UV filters and pigments evenly through a sunscreen. It builds smooth, stable textures and conditions the skin, and is common in gentle, skin-friendly formulas.

What is Polyglyceryl-4 Isostearate and what does it do in sunscreen?

Polyglyceryl-4 Isostearate is a mild, plant-derived emulsifier. It blends the oil and water phases of a sunscreen so the UV filters and any pigments stay evenly spread. It also conditions the skin and helps the formula feel smooth and stable.

Is Polyglyceryl-4 Isostearate safe?

Yes. It is part of the polyglyceryl family of emulsifiers, made from glycerin and the fatty acid isostearic acid, both gentle and widely used. Used at the low levels needed to structure a cream, it is considered non-irritating for most people.

Does Polyglyceryl-4 Isostearate clog pores?

Generally no. It is not flagged as comedogenic in our data and works as an emulsifier that holds the formula together rather than a heavy oil sitting in pores. Breakouts are far more often linked to the richer oils and waxes in a product than to a mild emulsifier like this.

Is Polyglyceryl-4 Isostearate fungal-acne safe?

Mostly, with one caveat. It is a fatty ester, and the malassezia yeast behind fungal acne can potentially use its fatty part, so people managing fungal acne may choose to avoid it. For everyone else it is harmless. This is one specific concern, not a broad safety problem.

Is Polyglyceryl-4 Isostearate natural or synthetic?

It is plant-derived but synthesized in a lab, made by joining glycerin with isostearic acid. The raw materials can come from natural sources, yet the finished emulsifier does not occur ready-made in nature. It is generally suitable for vegan formulas when the fatty acid is plant-sourced.

Sunscreens with Polyglyceryl-4 Isostearate

We rate 247 sunscreens that contain it, showing the top 10 by overall score:

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