What Is Peg-5 Hydrogenated Castor Oil Triisostearate?
Peg-5 Hydrogenated Castor Oil Triisostearate is a plant-derived ingredient created from castor oil that has been hydrogenated, reacted with about five units of ethylene oxide, then combined with isostearic acid. This process turns the thick natural oil into a smooth wax-like substance that mixes easily with both water and oil.
Castor oil has long been valued in soaps and ointments. In the mid-20th century chemists began modifying it to improve texture and stability in skin care. The Peg-5 version arrived as brands looked for gentle alternatives to harsh surfactants. By adding small amounts of polyethylene glycol (PEG) they made the oil water dispersible, while the hydrogenation step gave it a longer shelf life.
The finished material is produced in three main steps: hydrogenating raw castor oil to saturate its fatty chains, ethoxylating the oil to add the PEG “arms,” then esterifying it with isostearic acid. The result is a semi-solid paste or flakes that melt quickly into formulas.
You will most often see Peg-5 Hydrogenated Castor Oil Triisostearate in cleansing balms, makeup removers, milky lotions, sunscreen emulsions, cream masks and many leave-on moisturizers where a light, cushiony feel is desired.
Peg-5 Hydrogenated Castor Oil Triisostearate’s Cosmetic Benefits/Uses
This multi-tasker improves both how a product feels and how well it performs on the skin.
- Emulsifying: Helps oil and water stay blended so creams and lotions remain smooth, stable and easy to spread without separating over time.
- Viscosity controlling: Adds body and thickness to a formula giving it a rich yet non-greasy texture that glides on evenly and stays put.
Who Can Use Peg-5 Hydrogenated Castor Oil Triisostearate
This ingredient is generally well tolerated by most skin types including normal, dry, combination and oily skin. Its lightweight emollient character means it softens without leaving a heavy film, making it comfortable even for those prone to shine. Sensitive or highly reactive skin usually handles it well since it is considered low in irritation potential, though individuals with a known sensitivity to PEGs or castor derivatives should proceed with caution.
Peg-5 Hydrogenated Castor Oil Triisostearate is plant derived and made without animal by-products so it suits both vegetarians and vegans. The castor bean is its sole biological source.
Current safety data indicate it is not expected to pose a risk during pregnancy or while breastfeeding. That said this is not medical advice and anyone who is pregnant or nursing should share the full ingredient list of any new product with a healthcare professional before use.
The molecule does not make skin more sensitive to sunlight and it has no known effect on how SPF filters work. It is also fragrance free and free of common allergens like gluten and nuts so cross-reactivity is unlikely.
Potential Side Effects/Adverse Reactions
Reactions to topical Peg-5 Hydrogenated Castor Oil Triisostearate differ from person to person. The points below outline potential side effects yet most users will not encounter them when the ingredient is formulated and used correctly.
- Mild irritation – rare instances of redness or stinging, usually in very sensitive skin
- Contact dermatitis – isolated allergic responses in individuals with an existing PEG or castor allergy
- Eye discomfort – transient burning or watering if a product migrates into the eyes, largely relevant for cleansing oils and makeup removers
- Build-up related dullness – if used in heavy leave-on layers it can form a film that traps debris leading to a lackluster look, more common in those who do not cleanse thoroughly
If any of these effects occur discontinue use and seek advice from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 1 out of 5. The base oil is highly purified castor oil which on its own has a low clogging potential and the hydrogenation plus PEG modification make the molecules bulkier and more water friendly so they tend to sit on the surface and rinse away rather than lodging deep in pores. Laboratory data and user reports rarely link this ingredient to acne flare-ups even at higher use levels in cleansers or creams.
Because of its low rating Peg-5 Hydrogenated Castor Oil Triisostearate is generally considered suitable for skin that is prone to breakouts, provided the rest of the formula is also non-comedogenic.
Formula context matters. If the ingredient appears in a very heavy balm or sits on the skin without proper cleansing, any occlusive layer can still trap dead cells and sebum so product texture and routine play big roles in overall pore friendliness.
Summary
Peg-5 Hydrogenated Castor Oil Triisostearate acts mainly as an emulsifier and viscosity controller. Its dual water-and-oil loving structure pulls oily and watery phases together so lotions stay creamy and stable while its semi-solid waxy feel thickens formulas just enough to create a smooth cushioned glide.
It enjoys moderate popularity. You will spot it most often in cleansing balms makeup removers and lightweight creams though many brands still prefer traditional PEG-40 hydrogenated castor oil which means the Peg-5 version remains a bit of a niche choice for formulators seeking a gentler touch.
Safety studies and decades of cosmetic use point to a low risk profile with minimal irritation or allergy reports. As with any new skincare ingredient it is wise to patch test a fresh product before applying it to the entire face to ensure personal compatibility.