Triisononanoin

Triisononanoin is a glyceryl triester—a compound formed from glycerin combined with aliphatic (fatty) acids. It occurs naturally in plant and animal oils, and is used synthetically in skincare formulations as an emollient and viscosity controller.In products, it functions as an occlusive agent that sits on the skin surface to condition and soften, whilst also helping to control the thickness and texture of creams and oils. It is distinct from humectants, which draw water into the skin.

Triisononanoin is an occlusive emollient, meaning it forms a protective layer on the outer layer of skin. Rather than absorbing into deeper layers, it remains at the application site, where it conditions the stratum corneum (outer skin barrier) by smoothing and softening surface cells.In formulations, it also adjusts how the product feels and spreads, affecting its consistency and how readily it distributes across the skin.

Triisononanoin is typically incorporated into formulations by the manufacturer at concentrations ranging from less than 1% to around 10%, so you do not need to adjust your application. Use the product as directed on the label. It works well in both day and night routines and can be layered with other skincare steps.

Triisononanoin is generally well-tolerated and classified as safe for use in cosmetics. It is non-irritating and unlikely to cause sensitisation in most people, though those with very sensitive skin should patch-test new products as a precaution.