What Is Dierucic Acid?
Dierucic acid is a dimer of erucic acid, a long chain monounsaturated fatty acid that naturally occurs in high-erucic varieties of rapeseed and mustard seed. By joining two erucic acid molecules scientists create a 44-carbon fatty acid that is thicker and more stable than its single-chain parent. This extra heft makes it useful when a formula needs a rich emollient without a heavy waxy feel.
The cosmetic industry began exploring dierucic acid in the late 1980s when formulators were searching for plant-derived substitutes for mineral oils and synthetic emollients. Its similarity to skin lipids, combined with good oxidative stability, quickly made it attractive for leave-on products. Today many suppliers offer cosmetic-grade dierucic acid that meets strict purity standards.
Manufacturing starts with food-grade or industrial-grade erucic acid isolated from rapeseed oil. The acid is heated with a catalyst that encourages the double bonds of two erucic molecules to couple. After dimerization the mixture is purified and deodorized to remove odors and color, yielding a nearly odorless pale paste.
You will most often find dierucic acid in moisturizers, body and hand creams, barrier repair balms, night masks, lip care products, makeup primers, foundations and rich sunscreens. It can also appear in certain hair conditioners where extra slip and softness are desired, although its primary home is skin care.
Dierucic Acid’s Cosmetic Benefits/Uses
In formulations dierucic acid serves a single yet valuable purpose: skin conditioning. As an emollient it fills in microscopic gaps between skin cells, helping to smooth rough patches and soften the surface. Its long fatty chain forms a light occlusive layer that slows water loss, so skin feels moisturized for longer. Because the molecule is plant-derived and has low odor it blends well with both natural and synthetic actives, giving chemists a flexible alternative to petrolatum without a greasy after-feel.
Who Can Use Dierucic Acid
Dierucic acid suits most skin types including normal, dry and mature skin thanks to its rich emollient character. Oily or acne-prone skin may find it a bit heavy, and those users might prefer lighter conditioners that feel less occlusive.
The ingredient is plant derived from rapeseed so it is compatible with vegan and vegetarian lifestyles. No animal products or by-products are used in its manufacture.
Current data shows no specific risks for pregnant or breastfeeding women when dierucic acid is applied topically in cosmetic amounts. This is not medical advice and anyone who is expecting or nursing should have their practitioner review all skincare choices to be safe.
Dierucic acid does not increase photosensitivity and it plays well with everyday sunscreen filters. It also carries very little scent which makes it a friendly option for people bothered by strong fragrances.
Potential Side Effects/Adverse Reactions
Side effects and reactions to the topical use of dierucic acid can vary from person to person. The following points describe potential issues that could appear yet they remain uncommon when the ingredient is used at typical cosmetic levels.
- Mild skin irritation such as redness, itching or burning
- Transient breakout or pore congestion on very oily or acne-prone skin
- Allergic contact dermatitis in individuals sensitive to fatty acids or rapeseed derivatives
- Greasy or heavy afterfeel if overapplied which may reduce product wearability
- Enhanced absorption of other actives that could amplify their own irritant potential
If any uncomfortable reaction develops stop using the product and seek advice from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 2 out of 5. Dierucic acid is a very long chain fatty acid that sits mostly on the surface, so it is less likely to wedge into pores than shorter, more mobile oils. Still, it forms an occlusive film that can trap dead cells and sebum in skin that already overproduces oil, making breakouts possible for some users. People who are easily clogged or have active acne may want to use it sparingly or choose lighter emollients. Because it is plant derived and highly purified, impurities that often cause congestion are minimal which keeps the rating on the lower side.
Summary
Dierucic acid is valued as a plant based emollient that smooths, softens and reinforces the skin’s moisture barrier by filling in microscopic gaps and slowing water loss. Its long fatty structure lets it coat the surface without a waxy feel so formulas stay rich yet spreadable. While not a headline ingredient it has a quiet niche following among formulators looking to replace petrolatum or silicones in moisturizing creams, balms and makeup bases.
Current safety data shows low risk of irritation or sensitization when used in cosmetic concentrations. Still, everyone’s skin is different so it is wise to patch test any new product that features dierucic acid before adding it to a daily routine.