What Is Diisostearyl Fumarate?
Diisostearyl Fumarate is an ester created by combining fumaric acid with isostearyl alcohol, giving it the long official name 2-Butenedioic acid (2E), bis(16-methylheptadecyl) ester. Both starting materials come from plant-derived fatty acids, which are reacted under controlled heat and pressure to form a smooth, wax-like substance. First explored in the late 1970s as a way to replace heavier mineral oils, it quickly found its niche in color cosmetics where a silky non-greasy feel was needed. Today you will spot it in lipsticks, balms, foundations, cream blushes, moisturizers and anti-aging lotions because it melts at skin temperature and leaves a soft flexible film.
Diisostearyl Fumarate’s Cosmetic Benefits/Uses
This ingredient earns its place in formulas by improving how a product feels and how it treats the skin.
- Skin Conditioning: Helps maintain skin softness and suppleness by forming a light occlusive layer that slows water loss, so skin stays comfortably hydrated throughout the day.
- Emollient: Fills in tiny gaps between skin cells creating a smooth even surface which gives makeup better glide, prevents flaking and adds a luxurious cushiony texture.
Who Can Use Diisostearyl Fumarate
Thanks to its light non-greasy texture, Diisostearyl Fumarate is generally well suited for dry, normal and combination skin. Oily or acne-prone skin can usually tolerate it too because it is less heavy than classic plant butters and mineral oils, though very blemish-prone users may prefer to patch test first with the finished product. Sensitive skin tends to do well since the ingredient has a low irritation profile.
The ester is sourced from plant-derived fatty acids so it is considered suitable for vegans and vegetarians. No animal by-products are used during production.
There is no data showing that topical Diisostearyl Fumarate poses a risk during pregnancy or breastfeeding when used in cosmetic amounts. This is not medical advice and anyone who is pregnant or nursing should ask a healthcare professional before adding new skincare just to be safe.
The ingredient does not make skin more sensitive to sunlight and can be worn during the day without increasing the risk of sunburn. It also plays well with common actives like retinoids, vitamin C and acids, making it an easy addition to most routines.
Potential Side Effects/Adverse Reactions
Side effects from topical use of Diisostearyl Fumarate vary from person to person. The following are potential reactions that could happen, but most users will not experience them when the ingredient is used correctly in a finished product.
- Mild redness or stinging on very sensitive skin
- Contact allergy leading to itching or small rash
- Temporary clogged pores in individuals prone to comedones
If any unwanted reaction occurs discontinue use and consult a medical professional.
Comedogenic Rating
Diisostearyl Fumarate scores a 1 on the 0-5 comedogenic scale. Its branched fatty chains spread easily without forming a thick occlusive layer, so it is far less likely to block pores than heavier plant butters or straight-chain oils. Most acne-prone users can use it without worsening breakouts. Because it is wax-like and semi-solid, formulas that use a very high level of this ester in combination with other rich ingredients could still feel heavy on extremely oily skin.
Summary
Diisostearyl Fumarate works primarily as a skin-conditioning emollient, smoothing rough patches and locking light moisture onto the surface by creating a flexible breathable film. This gives makeup cleaner glide and leaves skincare with a soft non-greasy afterfeel. It has carved out a steady niche in lipsticks balms and cream color products but remains a supporting player rather than a headline ingredient.
Safety data show a low risk of irritation or sensitization when used at cosmetic concentrations, and the ester is vegan friendly. As with any new product it is wise to run a quick patch test first to be sure your individual skin agrees with the formula.