Phytosteryl Isostearate

Phytosteryl isostearate is a conditioning agent derived from plant sterols—naturally occurring compounds found in seeds, oils and grains. It is created by combining phytosterols with isostearic acid, resulting in an ingredient that functions as both a skin and hair conditioner in cosmetic formulations.In skincare products, it works primarily as an occlusive emollient, helping to coat and soften the skin surface. It appears in a relatively small proportion of products (around 0.1%), typically in creams, lotions and balms.

Phytosteryl isostearate is an occlusive emollient, meaning it sits on the skin surface and reduces water evaporation. This helps maintain hydration and can improve the overall feel and appearance of dry or compromised skin.The ingredient also has mild emulsifying properties, allowing it to blend oil and water phases in a formulation whilst simultaneously conditioning the skin.

Phytosteryl isostearate is typically incorporated by manufacturers into finished products; there is no need for separate application guidance. Use the product as directed on the label. In creams and balms where it appears, apply to clean, damp skin for optimal hydration benefit, as occlusives work best when they seal in existing moisture.

Phytosteryl isostearate is generally well-tolerated and considered safe for cosmetic use. It is unlikely to trigger irritation in most skin types, though those with specific sensitivities to plant-derived ingredients should patch-test first.