What Is Peg-40 Ricinoleamide?
Peg-40 Ricinoleamide is a synthetic ingredient made by bonding about forty units of ethylene oxide to ricinoleic acid, a fatty acid that comes from castor oil. The result is a water-friendly substance that still carries the softening traits of the original plant oil. First explored in the mid-20th century when formulators were looking for gentler ways to wash skin and hair, it soon became popular for its ability to mix oil and water without heavy feel or strong scent.
To make it, manufacturers start with castor oil, isolate the ricinoleic acid and turn it into an amide by reacting it with a simple nitrogen source. They then add controlled amounts of ethylene oxide in a step called ethoxylation, which gives the final material its “PEG-40” label. Careful purification follows to remove leftovers from the reaction and to meet safety standards.
You will spot Peg-40 Ricinoleamide in many rinse-off and leave-on formulas. It shows up in facial cleansers, micellar waters, shower gels, shampoos, makeup removers, wipes, lightweight lotions, spray conditioners, sheet masks and even some sun care products where an easy-to-wash texture is desired.
Peg-40 Ricinoleamide’s Cosmetic Benefits/Uses
In everyday beauty products Peg-40 Ricinoleamide plays two key roles that keep formulas stable and pleasant to use.
- Cleansing: It grabs onto dirt, oil and makeup so they can be rinsed away with water. This helps cleansers work well without the need for harsher detergents, leaving skin and hair feeling fresh yet comfortable.
- Emulsifying: It acts like a bridge between water and oil, letting them stay blended. This gives creams, lotions and cleansing oils a smooth, even texture and prevents the layers from separating during storage.
Who Can Use Peg-40 Ricinoleamide
This ingredient is generally well tolerated by all skin types including oily, dry, combination and sensitive skin because it is mild and non stripping. People with very reactive or allergy prone skin should still check the full formula for other triggers but Peg-40 Ricinoleamide itself is not known to aggravate common conditions such as eczema or rosacea.
Since it is synthesized from castor oil and does not involve any animal derived matter the ingredient is suitable for vegans and vegetarians.
Current safety data show no specific risks for pregnant or breastfeeding women when the ingredient is used in normal cosmetic concentrations. That said this is not medical advice and anyone expecting or nursing should run any skincare product past a qualified doctor to be on the safe side.
Peg-40 Ricinoleamide is not phototoxic so it does not increase sensitivity to sunlight. It rinses away easily and leaves no film that would interact with UV exposure.
Potential Side Effects/Adverse Reactions
Individual responses to topical Peg-40 Ricinoleamide can differ. The points below list potential side effects that might occur even though most users will not experience them when the ingredient is formulated and used correctly.
- Mild skin irritation such as redness or itching in people with very sensitive skin
- Eye stinging if a formula containing the ingredient is accidentally rubbed into the eyes
- Contact dermatitis in rare cases where a person is specifically allergic to castor derivatives or polyethylene glycols
- Scalp dryness or flakiness if a hair product with high levels of the ingredient is left on for prolonged periods
Stop using the product and seek professional advice if any adverse reaction occurs.
Comedogenic Rating
Rating: 1/5. Peg-40 Ricinoleamide is highly water soluble and used in low amounts so it does not build up in pores the way heavier oils or waxes can. Its castor oil origin does not carry over the thicker residue of the raw plant oil because the ethoxylation process makes the molecule rinse off easily. For these reasons it sits at the low end of the comedogenic scale.
Suitable for acne-prone or breakout-prone skin in most cases.
Some formulas pair Peg-40 Ricinoleamide with richer emollients that could raise the overall pore-clogging risk, so the full ingredient list still matters.
Summary
Peg-40 Ricinoleamide works as a gentle cleanser and an emulsifier. Its water-loving PEG chains latch onto grime while its fatty tail grabs oils, letting everything wash away cleanly. The same dual nature helps keep oil and water phases blended so creams and gels stay uniform from first pump to last.
It is a long-standing workhorse found in shampoos, facial cleansers, micellar waters and a variety of budget to mid-range products, though newer surfactants sometimes steal the spotlight.
Overall safety data are solid with low irritation and allergen potential when used at typical cosmetic levels. As with any new product give it a quick patch test to be sure it agrees with your skin.