Caprylic/Capric Triglyceride

Caprylic/capric triglyceride is a lightweight, colourless-to-pale-yellow oily liquid used as an emollient and carrier oil. The Cosmetic Ingredient Review defines it as the mixed triester of glycerin with caprylic (C8) and capric (C10) acids, two medium-chain saturated fatty acids. It is typically made from coconut oil: the oil is hydrolysed, the free glycerine removed, the medium-chain fatty acids separated by fractional distillation, then blended in a set ratio and re-esterified with glycerine.

That processing matters, because the finished ingredient behaves nothing like raw coconut oil. It is a thin, virtually odourless liquid that spreads easily and sinks in quickly, without the waxy lauric acid content or the solid-at-room-temperature texture of the oil it came from. Its fatty acids are fully saturated, so it also resists going rancid better than most plant oils, which is part of why formulators reach for it so often.

You will find it almost everywhere: cleansing oils and balms, serums, moisturisers, sun care, foundations, lipsticks and makeup removers. Industry data compiled by the CIR recorded it in around 6,000 cosmetic formulations, making it by far the most widely used triglyceride in cosmetics. Its listed functions are skin conditioning (occlusive), non-aqueous viscosity control and solvent. In plain terms, it moisturises, adjusts how a product feels and spreads, and dissolves oil-soluble ingredients such as vitamin E, retinol and UV filters so they disperse evenly through a formula.

Its effect on skin comes down to where it sits. The molecule is large and strongly oil-loving, so most of what you apply stays on the surface and within the stratum corneum, the outermost layer of flattened cells.

Sitting there it does two things at once. As an emollient it settles into the microscopic gaps between loose surface cells, smoothing their ragged edges so skin feels softer straight away and looks more even. It also leaves a thin film that slows how quickly water evaporates, so the moisture already held in the upper layers stays put for longer.

Chain length is what makes that film possible. Its two fatty acids are medium-chain, at eight and ten carbons, so the molecule is smaller and runnier than the long-chain triglycerides in most plant oils and butters. It stays liquid at room temperature and thins under the warmth of your fingertips, spreading into a continuous layer rather than thick patches.

The published human evidence is limited but consistent with this. In one study, an emollient emulsion containing 15% caprylic/capric triglyceride significantly raised surface hydration readings and significantly reduced measured water loss over the treated area. This ingredient is studied and used as a formulation base rather than as an active, so most research looks at finished formulas rather than the ingredient alone.

Caprylic/capric triglyceride is a base ingredient, so you almost never use it alone. What matters is recognising it on a label and knowing what it tells you about a product.

• Look for it high in the ingredients list if you want a richer, more cushioned moisturiser; low down, it is mostly there for texture.
• It has no pH requirement of its own and is not affected by acids, retinoids or vitamin C, so it layers with anything.
• Fine morning and night, and suitable for daily use.
• Apply oil-based products containing it after your water-based serums, not before, or you will slow the lighter layers down.
• In a cleansing oil or balm it is the part that dissolves sunscreen and makeup; follow with a gentle water-based wash if your skin feels coated.
• For dry or flaky skin, apply it over slightly damp skin so the film it leaves has more moisture to hold in.
• If you are congestion-prone, patch test a new rich formula on a small area for a week before using it across your whole face.