Polyglyceryl-4 Polycastorate/Hempseedate: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: July 1, 2025
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We verify all information on this page using publicly available nomenclature standards from The Personal Care Products Council (PCPC), the European Commission's CosIng database and documentation provided directly by ingredient manufacturers. Our analysis is based on technical data from these sources to ensure accuracy and reliability.

What Is Polyglyceryl-4 Polycastorate/Hempseedate?

Polyglyceryl-4 Polycastorate/Hempseedate is a plant-derived ingredient created when polyglycerin-4 is mixed with castor seed oil and hemp seed oil through a process called transesterification. The result is a biodegradable, oil-friendly compound that helps water and oil stay blended. Both castor and hemp seed oils have long histories in skin care for their fatty acids, while polyglycerin-4 is valued for its mildness. Chemists combined them to get an emulsifier that is gentle, renewable and suitable for modern clean beauty formulas.

Production starts with glycerin, usually sourced from vegetable oil, which is heated to link four glycerin units together. This polyglycerin-4 is then reacted with refined castor and hemp seed oils under controlled heat and pressure. The oils’ fatty acid chains swap places with parts of the polyglycerin, making a new molecule that has a water-loving side and an oil-loving side. After purification the finished material is a soft, amber liquid that dissolves easily into oil phases.

You will most often see Polyglyceryl-4 Polycastorate/Hempseedate in moisturizers, facial and body lotions, sunscreens, creamy cleansers, balms, makeup foundations and sheet mask essences. Brands choose it when they want plant-based, PEG-free emulsification that feels light yet stable on the skin.

Polyglyceryl-4 Polycastorate/Hempseedate’s Cosmetic Benefits/Uses

This ingredient plays one key role in personal care formulas.

Emulsifying: It binds water and oil into a smooth, uniform mixture so products do not separate in the bottle and spread evenly on the skin. A reliable emulsifier improves texture, boosts the performance of active ingredients and gives a pleasant, non-greasy finish that consumers enjoy.

Who Can Use Polyglyceryl-4 Polycastorate/Hempseedate

This emulsifier is generally well tolerated by all skin types, including normal, dry, oily, combination and even sensitive or acne-prone skin. Its lightweight feel and low potential for clogging pores make it a versatile choice in many formulations.

Because it is produced entirely from plant sources it is suitable for vegans and vegetarians. No animal derivatives or by-products are used at any point in its manufacturing process.

Current research shows no specific concerns for pregnant or breastfeeding women when this ingredient is applied topically in cosmetic amounts. That said, this is not medical advice and anyone who is pregnant or nursing should clear any skincare products with their healthcare provider to be safe

Polyglyceryl-4 Polycastorate/Hempseedate does not cause photosensitivity, so it will not make skin more prone to sunburn. It is also odorless and free of common fragrance allergens, which further supports its compatibility with sensitive complexions.

Potential Side Effects/Adverse Reactions

Responses to topical Polyglyceryl-4 Polycastorate/Hempseedate can vary from person to person. The following points cover potential side effects, but most users will not notice any problems when the ingredient is properly formulated in a product.

  • Mild temporary redness or stinging in very sensitive skin
  • Rare allergic contact dermatitis for individuals already sensitized to castor or hemp seed derivatives
  • Very slight chance of clogged pores when used in extremely heavy, occlusive formulas

If you notice irritation or any other unwanted reaction discontinue use and consult a healthcare professional

Comedogenic Rating

Rating: 1/5 – Polyglyceryl-4 Polycastorate/Hempseedate scores very low on the comedogenic scale. Although castor oil can be mildly occlusive on its own, binding it to a polyglycerin backbone and blending it with lightweight hemp seed fatty acids makes the final molecule far less likely to settle into pores. Its water-loving section also helps it rinse away cleanly, reducing buildup over time. This makes it generally a safe pick for people who break out easily. Only exceptionally heavy formulations or very high use levels might tip the balance toward congestion.

Because the ingredient is used at modest percentages and is readily biodegradable, residue that could linger on skin is minimal. Still, very oily skin types who find any rich texture problematic might prefer lighter emulsifiers.

Summary

Polyglyceryl-4 Polycastorate/Hempseedate is a plant-based emulsifier that keeps water and oil blended, stabilises textures and leaves a light, non-greasy finish. Chemists achieve this by linking four glycerin units to fatty acids from castor and hemp seed oils, creating a molecule with both water-loving and oil-loving halves that naturally hold a formula together.

It is gaining traction in clean beauty circles but is not yet as common as legacy emulsifiers like polysorbates. Brands looking for PEG-free, vegan options are helping its popularity rise.

Safety data so far show it to be gentle for nearly all skin types with a very low likelihood of clogging pores or causing irritation. As with any new skincare product it is wise to patch test before full use, especially if your skin is reactive.

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