Emollient

Octadecane

INCI: OCTADECANE

Reviewed by Emma · Last updated 14 Aug 2026

A lightweight hydrocarbon that conditions skin and helps formulations spread evenly

Best For Skin Types

All, Dry, Combination, Mature

Addresses

Dryness, Barrier repair

Usage Frequency

Daily

What Is Octadecane?

Octadecane is a long-chain hydrocarbon—a naturally occurring organic compound found in plants, animals, and mineral sources. In skincare formulations, it functions as an emollient and skin conditioner, helping to soften and smooth the skin surface whilst improving the texture and spreadability of products.

Its role is largely structural within a formula rather than delivering active benefits. It works as a non-polar solvent and conditioning agent, making it a common inclusion in moisturisers, serums, and other leave-on treatments where a light, uniform application is desired.

How It Works

Octadecane is a non-polar ingredient, which means it works well with oils and lipids rather than water. On the skin, it forms a light conditioning film that helps reduce transepidermal water loss and maintains skin softness. This mechanism is similar to how other occlusive and emollient ingredients work, though octadecane is typically lighter in feel than heavier oils.

Within a formula, octadecane acts as a solvent, helping to dissolve and blend other ingredients uniformly throughout the product. This improves consistency and ensures even application to the skin.

Clinical Evidence & References

The published research on octadecane in skincare is limited. Most evidence derives from its use in synthetic ceramide formulations—specifically compounds like 2-N-oleoylamino-octadecane-1,3-diol, which is a ceramide analogue. These studies focus on synthesis and characterisation rather than efficacy in skin health.

Octadecane itself has been studied for non-skincare applications, including surface texture and hydrophobic properties in materials science. Whilst these findings are interesting, they do not directly confirm benefits when applied to human skin. As a conditioning and solvent agent, octadecane is presumed effective based on its established chemical properties and widespread industry use, but dedicated clinical trials on skin outcomes are not readily available.

How to Use

Octadecane is a supporting ingredient rather than an active one, so there is no need to use it in isolation. It will be present as part of a complete formulation—typically in moisturisers, serums, or other conditioners. Apply products containing octadecane as directed on the packaging, usually once or twice daily to clean, dry skin.

Safety & Precautions

Octadecane is generally well-tolerated and is used safely in cosmetics across a wide range of skin types. It has a low risk of irritation or sensitisation. As with any ingredient, discontinue use if unusual redness, itching, or irritation develops.

Frequently Asked Questions

From the Clinic

Not sure what your skin actually needs?

Two minutes, a few questions, and we’ll point you at what matters — no guesswork.

Take the skin quiz

Learn More About Skincare Ingredients

Explore our comprehensive ingredient glossary to understand what's in your products.

Browse All Ingredients

Authorised Stockist

Official UK retailer

Tracked Delivery

Free UK shipping over £50

5 Star Rating

Trusted by thousands

Expert Advice

Free consultations