What Is Hydrogenated Dimer Dilinoleth-40?
Hydrogenated Dimer Dilinoleth-40 is a lab-made ingredient derived from dimerized linoleic acid, a fatty acid that originally comes from vegetable oils like soybean or safflower. After the linoleic acid molecules are joined into a larger “dimer,” they are hydrogenated to make them more stable, then reacted with ethylene oxide about 40 times to create a polyethylene glycol (PEG) chain. The result is a waxy, water-dispersible substance that blends oil and water with ease.
The PEG modification was first explored in the 1970s when formulators looked for gentler, more effective surfactants to replace harsher soaps. Its ability to cleanse without stripping the skin, while also helping oil and water mix, quickly made it a staple in modern cosmetics.
Manufacturing starts with plant-based linoleic acid. Two of these fatty acid molecules are chemically linked, yielding a “dimer” that is then converted to an alcohol. Hydrogenation saturates the molecule, boosting shelf life and reducing scent. Finally, controlled ethoxylation adds the PEG chain, fine-tuning the ingredient’s solubility. With each step tightly monitored for purity, the finished material meets cosmetic-grade safety standards.
You will most often see Hydrogenated Dimer Dilinoleth-40 in rinse-off cleansers, facial masks, lightweight moisturizers, makeup removers and occasionally in hair conditioners where gentle cleansing and smooth texture are needed.
Hydrogenated Dimer Dilinoleth-40’s Cosmetic Benefits/Uses
In a formula this ingredient plays two key roles that improve both performance and feel
- Cleansing: Its surfactant nature lifts away dirt, oil and makeup while staying mild on skin, so products can clean effectively without leaving a tight or dry sensation
- Emulsifying: It binds water and oil phases into a stable, uniform mixture which keeps creams from separating improves spreadability and gives finished products a smooth, elegant texture
Who Can Use Hydrogenated Dimer Dilinoleth-40
This ingredient is considered gentle enough for most skin types including oily, combination, normal and sensitive. Its light surfactant action lifts oil without stripping so even acne-prone users usually tolerate it well. Extremely dry or eczema-prone skin may crave richer, more occlusive cleansers but Hydrogenated Dimer Dilinoleth-40 itself is not known to worsen dryness.
Originating from plant oils and synthesized without animal by-products it is suitable for both vegetarians and vegans. The ethoxylation step uses petroleum-derived ethylene oxide yet this does not affect its animal-free status.
No specific warnings exist for women who are pregnant or breastfeeding. Current safety data show no hormonal or systemic concerns from topical use. That said this is not medical advice and anyone who is expecting or nursing should ask their doctor before adding new skincare products.
The molecule is not photoactive so it does not make skin more sensitive to sunlight. It is also fragrance-free naturally and carries almost no scent which lowers the risk of scent-related irritation.
Potential Side Effects/Adverse Reactions
Responses to any cosmetic ingredient can differ from person to person. The effects listed below are possible but uncommon when the formula is made and used correctly.
- Mild skin irritation – a short-lived stinging or redness, most often in people with compromised skin barriers
- Contact dermatitis – rare allergic reaction marked by itching, rash or swelling
- Eye irritation – if a cleanser containing it gets into the eyes it may cause temporary watering or discomfort
- Follicular congestion – very uncommon clogged pores in those highly prone to comedones
If any of these reactions occur stop using the product and consult a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 1/5
Hydrogenated Dimer Dilinoleth-40 is mostly water-dispersible and does not leave a greasy film on the skin, so it has little chance of blocking pores. Its large PEG chain keeps it sitting on the surface and rinsing away easily, which further lowers the risk of clogging. Because it is still derived from fatty acids a slight chance of buildup exists in very pore-clogging-prone users, which is why it is rated 1 rather than 0.
Suitable for acne-prone skin in most cases
Formulation can shift the real-world effect: a heavy cream packed with oils may still feel occlusive even if this ingredient itself is low on the scale.
Summary
Hydrogenated Dimer Dilinoleth-40 works as a mild cleanser and an emulsifier. Its surfactant side lifts away dirt and makeup while its PEG-based structure grabs both oil and water so they can mix and rinse off together. This dual action lets formulators create silky cleansers masks makeup removers and light lotions that feel smooth and rinse clean.
It is not the most famous name on an ingredient list but it appears in a fair number of modern gentle cleansers and wipe-off products thanks to its balanced performance and skin-friendly feel.
Current safety reviews show a low risk of irritation allergy or pore clogging so most people can use it without worry. As with any new skincare step do a quick patch test first to make sure your skin agrees with the formula.