What Is Diisocetyl Adipate?
Diisocetyl Adipate, also listed on labels as Bis(2-hexyldecyl) adipate, is a clear oily liquid created by joining adipic acid with a long branched alcohol called 2-hexyldecyl alcohol. Both starting materials are made in modern chemical plants, so the final ingredient is considered synthetic. It first gained attention in the 1970s as a softening agent for flexible plastics. Formulators soon noticed that its silky feel, light weight and stability also suited skin care and makeup, so it was adopted by the cosmetic industry.
To make Diisocetyl Adipate, manufacturers heat adipic acid with the alcohol in the presence of a tiny amount of catalyst. Water is removed during the reaction, leaving behind the smooth ester we use in beauty products. This ingredient now appears in many formulas that need a light non-greasy touch, such as facial and body lotions, sunscreens, creamy cleansers, lipsticks, foundations, hair conditioners, masks and anti-aging serums.
Diisocetyl Adipate’s Cosmetic Benefits/Uses
Formulators choose Diisocetyl Adipate because it offers several helpful roles in one ingredient.
- Plasticiser – keeps films such as those formed by mascara, foundation or sunscreen flexible so they do not crack or flake during wear
- Skin conditioning – leaves a soft smooth finish on the skin improving overall feel and comfort
- Emollient – fills in tiny gaps between skin cells to reduce dryness and enhance a supple look without heaviness
- Solvent – helps dissolve other oil-soluble ingredients like pigments or UV filters so the final product is even and stable
Who Can Use Diisocetyl Adipate
Because it has a light silky texture Diisocetyl Adipate suits most skin types, especially normal and dry skin that need extra softness without a greasy afterfeel. Combination skin often tolerates it well too. Very oily or acne-prone skin may find formulas rich in this ester feel too occlusive which could contribute to clogged pores if the overall product is heavy or used in humid climates.
The ingredient is made entirely from synthetic raw materials so it does not contain, use or derive from animal sources. This makes it acceptable for vegans and vegetarians who wish to avoid animal-based ingredients.
No studies have flagged specific risks for women who are pregnant or breastfeeding when Diisocetyl Adipate is used topically at normal cosmetic levels. It stays on the surface of the skin and is not expected to enter the bloodstream in meaningful amounts. This is not medical advice and anyone who is pregnant or nursing should show any skincare product they plan to use to their doctor just to be safe.
Diisocetyl Adipate does not cause photosensitivity. In fact it is often paired with UV filters in sunscreens to improve their spread and performance so daytime use is perfectly fine.
Potential Side Effects/Adverse Reactions
Side effects and reactions to the topical application of Diisocetyl Adipate vary from person to person. The points below list potential issues and are highly unlikely to reflect the experience of most users when the ingredient is formulated and used correctly.
- Mild skin irritation or redness in very sensitive individuals
- Contact allergy presenting as itching, rash or hives (rare)
- Breakouts or comedones on acne-prone skin when used in heavy formulations
- Eye stinging or watering if the product accidentally gets into the eyes
- Folliculitis (inflamed hair follicles) in areas where occlusive products are layered repeatedly
If any unwanted reaction occurs stop using the product immediately and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 2 out of 5. Diisocetyl Adipate has a light silky texture and spreads easily without leaving a heavy film, which keeps its pore-clogging potential relatively low. Still, it is a fatty ester that can contribute to build-up when used in richer formulations or layered with other occlusive ingredients, so it earns a mild to moderate rating rather than a zero. Most people will not notice clogged pores from products containing small to moderate amounts of this ester, but those who are very prone to acne or live in hot humid climates might prefer lighter alternatives.
Bottom line: generally suitable for breakout-prone skin when used in lightweight formulas, yet it may be best avoided in thick creams or heavy makeup if you easily develop pimples.
Extra note: the finished product matters more than the single ingredient. A formula packed with waxes or butters may still feel heavy even if Diisocetyl Adipate itself is only mildly comedogenic.
Summary
Diisocetyl Adipate works as a plasticiser, skin conditioner, emollient and solvent. Its branched fatty structure softens films so makeup stays flexible, fills micro-gaps between skin cells for a smooth feel, and dissolves oil-soluble actives to keep formulas even and stable. These multitasking abilities make it a handy choice for lotions, sunscreens and color cosmetics, though it is more of a behind-the-scenes helper than a headline ingredient.
Overall safety is high when used as intended because it sits on the skin surface and shows a low rate of irritation or sensitisation. As with any new product it is wise to patch test first to be sure it agrees with your individual skin.