Peg-25 Hydrogenated Castor Oil: 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 Peg-25 Hydrogenated Castor Oil?

Peg-25 Hydrogenated Castor Oil is a plant-derived ingredient made from castor oil that has been both hydrogenated and combined with about 25 units of ethylene oxide. Hydrogenating castor oil turns its natural liquid form into a waxier, more stable substance, while the addition of ethylene oxide gives it water-loving qualities. This dual character allows the ingredient to mix oil and water smoothly, which is why it shows up in many modern personal care formulas.

Castor oil itself has been used in beauty routines for centuries thanks to its rich, thick texture. In the mid-20th century chemists began modifying castor oil to improve its feel and boost its usefulness in creams, lotions and cleansers. Peg-25 Hydrogenated Castor Oil is one of those results. It is produced in two main steps: first the natural castor oil is hydrogenated under controlled heat and pressure to saturate its fatty acids; then it is reacted with ethylene oxide in a process called ethoxylation. The final material is a soft solid or thick paste that disperses easily in both water and oil.

You are most likely to find Peg-25 Hydrogenated Castor Oil in facial cleansers, micellar waters, makeup removers, shampoos, conditioners, bath oils, body creams and some sheet mask essences. Its versatility makes it popular in products that need a gentle cleansing boost without stripping the skin or hair.

Peg-25 Hydrogenated Castor Oil’s Cosmetic Benefits/Uses

This ingredient lends two key benefits to beauty formulas

  • Cleansing: Its surfactant nature lifts away dirt, makeup and excess sebum then helps them rinse off with water, leaving skin or hair feeling fresh but not tight
  • Emulsifying: It binds oily ingredients with watery ones so creams stay smooth, lotions do not separate and cleansing oils turn milky on contact with water for easy rinse-off

Who Can Use Peg-25 Hydrogenated Castor Oil

This ingredient is generally well tolerated by all skin types, including dry, normal, combination, oily and even sensitive skin, because it cleanses without stripping the skin’s natural barrier. People with very oily skin might prefer lighter formulas but the ingredient itself is not a problem for them.

Peg-25 Hydrogenated Castor Oil comes from castor beans and contains no animal derivatives so it is suitable for both vegans and vegetarians. Its plant origin also makes it an option for those looking to avoid animal testing by choosing cruelty free brands that use it.

No studies link this ingredient to problems during pregnancy or while breastfeeding. Still, this is not medical advice and anyone who is pregnant or nursing should show the full product ingredient list to their doctor to be on the safe side.

The ingredient does not cause photosensitivity and will not make skin more prone to sunburn. It can be used day or night alongside sunscreen without special precautions.

Potential Side Effects/Adverse Reactions

Responses to topical Peg-25 Hydrogenated Castor Oil vary from person to person. The issues below are possible but unlikely when the ingredient is used at the levels found in finished cosmetics.

  • Mild redness or stinging in people with highly reactive skin
  • Allergic contact dermatitis in rare cases of castor bean sensitivity
  • Eye irritation if the product accidentally gets into the eyes
  • Greasy or heavy feel if used in very rich formulas on already oily skin
  • Trace 1,4-dioxane residues if the manufacturer has not properly purified the ingredient, though reputable brands remove this contaminant

If you notice any of these effects stop using the product and consult a healthcare professional if symptoms persist or worsen

Comedogenic Rating

Rating: 1/5. Peg-25 Hydrogenated Castor Oil has a low tendency to block pores because the hydrogenation and ethoxylation steps make the molecule more water dispersible and less likely to sit in the follicle the way pure oils can. Most of it rinses away with water during cleansing and in leave-on products it is typically used at low levels that do not create an occlusive film. People prone to acne can usually use formulas containing this ingredient without extra concern, though product texture and the presence of heavier oils can still influence breakouts. Its low rating also reflects the fact that current cosmetic literature reports very few cases of acne caused by ethoxylated castor derivatives.

Summary

Peg-25 Hydrogenated Castor Oil acts mainly as a cleanser and emulsifier. Its oil-friendly backbone grabs onto makeup, sunscreen and sebum while its ethoxylated segments bind to water, so debris can be lifted away and rinsed off. The same dual nature stabilizes emulsions so lotions, creams and cleansing balms stay smooth and uniform.

Although it is not as famous as hyaluronic acid or niacinamide, this ingredient is quietly popular in cleansers, micellar waters and milky makeup removers because it improves rinse-off and gives formulas a soft skin feel without adding greasiness.

Current safety assessments show Peg-25 Hydrogenated Castor Oil is non-sensitizing and non-toxic at the levels used in cosmetics, making it a low-risk choice for daily routines. As with any new skincare product a quick patch test is still wise since individual sensitivities vary.

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