Diisostearyl Malate

Diisostearyl Malate is a lipophilic emollient/texture agent commonly used in lip products and creams (often a few percent up to higher levels in color cosmetics) to improve slip and reduce moisture loss. Available human experience and patch-test data suggest it has a low irritation profile and is generally well tolerated, though any leave-on emollient can rarely trigger stinging or eczema flares in highly reactive individuals. Given its non-active nature but real-world exposure in compromised skin populations, I score it as very gentle rather than inert. Safety Notes: Diisostearyl Malate is primarily a leave-on emollient/film-former used to improve slip, gloss, and pigment wetting; in facial skincare (creams/serums/SPF) it often appears as a minor sensorial modifier around ~0.05–2%. In color cosmetics marketed to consumers (lip oils/glosses/lipsticks/balms), it can be a primary ester/oil phase component and is commonly seen in the ~5–30% band, with high-ester, anhydrous lip products and certain “treatment” balms reaching roughly 40–60%. It is uncommon in rinse-off formats and there are no specific EU/FDA concentration caps for this ingredient beyond general cosmetic safety requirements, so the upper end is driven by aesthetics/viscosity and anhydrous stability rather than regulation.