What Is Hydrogenated Dimer Dilinoleic Acid/Hexanediol Copolymer?
Hydrogenated Dimer Dilinoleic Acid/Hexanediol Copolymer is a man-made substance created by linking together two smaller building blocks: hydrogenated dimer dilinoleic acid, which comes from plant-based fatty acids, and hexanediol, a simple alcohol. When these pieces are joined they form a long, sturdy chain called a copolymer. The hydrogenation step adds stability so the final material resists breaking down when exposed to air or light.
The idea of using fatty acid polymers in beauty products dates back to the 1970s when chemists searched for gentle film formers to replace harsher resins. Over time the process was refined until this specific copolymer met modern safety and performance standards. Today it is produced in controlled factory settings where the raw fatty acids are first converted into dimer dilinoleic acid, then hydrogenated, combined with hexanediol and finally purified to remove residues.
Because it forms a flexible, water-resistant layer, you will spot this ingredient in a range of leave-on items such as moisturizers, face masks, long-wear foundations, sunscreens, hair gels and anti-frizz creams. Its smooth feel and protective nature also make it popular in lip balms, mascara and styling sprays.
Hydrogenated Dimer Dilinoleic Acid/Hexanediol Copolymer’s Cosmetic Benefits/Uses
This copolymer lends two key benefits to personal care formulas.
- Film forming: It spreads over skin or hair and dries into a thin breathable shield that locks in moisture, boosts wear time of makeup and helps active ingredients stay put even when exposed to sweat or water.
- Hair conditioning: The smooth film coats strands, reducing roughness and static so hair feels softer, looks shinier and is easier to comb without added weight.
Who Can Use Hydrogenated Dimer Dilinoleic Acid/Hexanediol Copolymer
This film forming copolymer is considered gentle enough for most skin types, including dry, normal and combination. Oily or acne-prone skin can usually tolerate it too because it forms a lightweight breathable layer that is not known to trap excessive oil, though those who clog easily may prefer to use it in rinse-off products rather than heavy leave-ons.
The ingredient is synthesized from plant-derived fatty acids and a lab-made alcohol, with no animal sourced components or by-products, making it suitable for vegans and vegetarians.
No data suggest any hormonal activity or systemic absorption at levels that would concern pregnant or breastfeeding women. That said this is not medical advice and anyone who is pregnant or nursing should clear all personal care products with a healthcare professional before use.
The copolymer does not increase photosensitivity and can safely be worn during daytime, including under sunscreen.
Because it is virtually odorless and nonvolatile it is often well tolerated by people who are sensitive to fragrance or strong solvents in cosmetics.
Potential Side Effects/Adverse Reactions
Side effects from topical Hydrogenated Dimer Dilinoleic Acid/Hexanediol Copolymer can vary from person to person. The points below outline potential issues, though they are unlikely for most users when the ingredient is properly formulated.
- Mild skin irritation such as redness or itching, especially on compromised or very sensitive skin
- Rare allergic contact dermatitis in individuals with specific sensitivities to fatty acid derivatives
- Temporary pore congestion or breakouts in people extremely prone to acne when used in very occlusive leave-on formulas
- Product buildup on hair leading to a heavy feel or reduced volume if not cleansed regularly
If any discomfort, rash or other unexpected reaction occurs discontinue use and seek advice from a medical professional.
Comedogenic Rating
Rating: 1/5 — This polymer sits on the surface in a flexible film rather than sinking into pores, so it is unlikely to clog them. Its fatty acid backbone is highly branched and hydrogenated, making the molecule bulky and stable which limits penetration and oxidation that could trigger breakouts. People prone to acne can generally use it without trouble, though very occlusive formulas containing high amounts of the copolymer could feel heavy on extremely oily skin.
The ingredient is typically combined with lightweight solvents and emulsifiers that further reduce any pore-blocking risk. As with any film former, proper cleansing at the end of the day helps prevent residue build-up that might contribute to congestion over time.
Summary
Hydrogenated Dimer Dilinoleic Acid/Hexanediol Copolymer acts mainly as a film former and hair conditioner. Its long, hydrogenated chain spreads into a smooth shield that locks in moisture, improves makeup wear time and tames frizz without stiffness. Because it delivers these benefits at low concentrations and feels light, formulators reach for it in everything from primers and long-wear foundations to anti-humidity hair sprays, though it is not as headline-grabbing as silicones or plant butters so you may not notice it on every label.
Safety reviews rate it as low risk for irritation, sensitization or systemic absorption. Most skin types tolerate it well, yet it is always smart to patch test any new product to be certain it meshes with your individual skin needs.