Carrier Oils & Butters

Facial Oils vs Moisturisers

Published 8 June 2026

When it comes to skincare, facial oils and moisturisers are often grouped together, but they serve very different biological functions within the skin. Moisturisers are primarily designed to increase hydration by attracting and retaining water within the stratum corneum, the outermost layer of the epidermis. They typically contain humectants such as glycerin and hyaluronic acid that help improve water content, supporting skin elasticity, enzyme activity and overall barrier function. Well hydrated skin generally appears smoother, more supple and better equipped to maintain its natural protective functions.

Facial oils work through a different mechanism. Rather than increasing water content, they provide lipids that help reinforce the skin's natural barrier and reduce transepidermal water loss. Many botanical oils contain essential fatty acids, antioxidants and phytosterols that support barrier integrity and help protect against environmental stressors. While moisturisers focus on hydration, facial oils help preserve that hydration by strengthening the lipid matrix that surrounds skin cells. For this reason, the two are often most effective when used together, with moisturisers supplying water and oils helping to retain it, creating a more resilient, balanced and healthy looking complexion.

Facial Oils vs Moisturisers

Why Are They Often Confused?

Facial oils and moisturisers are commonly grouped together because both contribute to healthier looking skin, yet they achieve this through different biological mechanisms. The confusion often arises because both products can leave the skin feeling softer, smoother and more comfortable after application. However, from a skin physiology perspective, they target different components of the skin barrier.

The outermost layer of the skin, known as the stratum corneum, consists of skin cells embedded within a lipid matrix composed primarily of ceramides, cholesterol and fatty acids. This structure is responsible for maintaining hydration and protecting against environmental stressors. Effective skincare aims to support both the water content and lipid content of this barrier. Moisturisers primarily address hydration, while facial oils primarily support lipid replenishment and barrier reinforcement.

Understanding this distinction is important because healthy skin depends on maintaining both adequate water levels and a well functioning lipid barrier. Deficiencies in either can contribute to dryness, roughness and impaired barrier function.

What Does a Moisturiser Do?

A moisturiser's primary role is to improve hydration within the stratum corneum. Most modern moisturisers contain a combination of humectants, emollients and barrier supporting ingredients that work together to optimise skin hydration and comfort. Humectants such as glycerin, hyaluronic acid and sodium PCA attract water from deeper layers of the skin and the surrounding environment. This increased water content improves skin flexibility, smoothness and elasticity. Research has shown that adequate hydration supports enzymatic activity within the skin, which is essential for normal barrier maintenance and skin renewal processes.

Moisturisers also commonly contain emollients that fill microscopic gaps between skin cells. This helps create a smoother skin surface and reduces the sensation of roughness. Some formulations additionally include barrier supporting ingredients such as ceramides, which mimic components naturally found within healthy skin.

By increasing water content and supporting barrier function, moisturisers help maintain skin homeostasis, which is essential for optimal skin health and resilience.

What Does a Facial Oil Do?

Facial oils function primarily by supporting the skin's lipid barrier rather than increasing hydration directly. They contain naturally occurring fatty acids and lipid compounds that help supplement the skin's protective surface. The skin barrier relies heavily on lipids to prevent excessive transepidermal water loss, the continuous evaporation of water from the skin into the environment. When the lipid barrier becomes compromised, moisture escapes more readily, leading to dehydration and reduced barrier efficiency.

Botanical oils contain varying profiles of fatty acids that interact differently with the skin. Oils rich in linoleic acid are often associated with barrier support and a lighter skin feel, while oils containing higher concentrations of oleic acid tend to provide greater emollient properties and enhanced softness. Many facial oils also contain naturally occurring antioxidants, including tocopherols, carotenoids and polyphenols. These compounds help neutralise free radicals generated by ultraviolet radiation, pollution and other environmental stressors. Reducing oxidative stress supports the skin's natural defence systems and contributes to a healthier looking complexion over time.

Hydration vs Barrier Support

One of the most common misconceptions in skincare is the belief that oils hydrate the skin. Scientifically, hydration refers specifically to water content within the epidermis. Since oils do not contain water, they cannot directly increase skin hydration in the same way that humectant based moisturisers can. Instead, facial oils help preserve existing hydration by reducing water evaporation from the skin surface. This distinction is important because hydrated skin requires both sufficient water and an intact lipid barrier.

Think of the skin barrier as a reservoir. Moisturisers help add water to the reservoir, while facial oils help prevent that water from escaping. Without adequate hydration, the skin may feel tight and uncomfortable. Without sufficient barrier support, hydration may be lost more rapidly.

Modern skin science increasingly recognises that both hydration management and lipid barrier integrity are essential components of healthy skin function.

Why They Work Better Together

The skin naturally contains both water and lipids, and optimal barrier function depends on maintaining an appropriate balance between the two. This is why moisturisers and facial oils often complement each other exceptionally well. Applying a moisturiser first helps increase water content within the outer layers of the skin. Following with a facial oil can help reinforce the lipid barrier and reduce subsequent water loss. This layered approach supports both hydration and moisture retention simultaneously.

Research into barrier function consistently demonstrates that skin performs best when both hydration levels and lipid organisation are maintained. When either component becomes deficient, barrier performance declines and the skin may become more vulnerable to environmental stressors. For individuals experiencing dryness, seasonal dehydration or compromised barrier function, combining both products often provides more comprehensive support than relying on either product category alone.

Which One Should You Choose?

The most suitable approach depends on individual skin physiology, environmental conditions and skincare goals.Dry skin typically benefits from both hydration and lipid replenishment because it often exhibits reduced water content and diminished barrier function. Mature skin may similarly benefit due to age related reductions in natural lipid production and slower barrier recovery. Combination and oily skin are often misunderstood. Even skin that produces excess sebum can experience dehydration and barrier disruption. Lightweight botanical oils with balanced fatty acid profiles may help support barrier function without creating a heavy skin feel.

Climate also plays an important role. Cold weather, low humidity, indoor heating and excessive cleansing can all increase transepidermal water loss. During these periods, additional barrier support may become particularly beneficial. Rather than selecting products solely based on skin type labels, it is often more effective to assess whether the skin requires additional hydration, barrier support or both.

The Takeaway

Facial oils and moisturisers are not competing products. They support different but equally important aspects of skin physiology. Moisturisers focus primarily on increasing and maintaining water content within the skin, while facial oils help reinforce the lipid barrier and minimise moisture loss.

Together, they address two of the most fundamental requirements for healthy skin: hydration and barrier integrity. By understanding the science behind how these products function, it becomes easier to create a skincare routine that supports long term skin health, improves resilience against environmental stressors and promotes a smoother, more balanced and radiant complexion.