Squalene is a natural antioxidant compound that is found in varying amounts in both animal and plant sources.¹ It is classified as a triterpene hydrocarbon (highly unsaturated), and is a natural lipid that is a major intermediate in the biosynthesis of cholesterol in the liver.^{1, 2}

In nature, the highest levels of squalene can be found among olives, sharks, liver oil, wheat germ and rice bran.² The main animal source of squalene is sourced from certain deep-sea shark varieties. For consumers seeking products containing a plant-based squalene source, olive tree offers a viable alternative.

Squalene is found in high amounts in Virgin Olive Oils – ranging from 0.8 to 13 g/kg, depending on the olive cultivar, oil extraction technology and the level of refining.³ Extra Virgin Olive Oil, being the fresh juice of the olive fruit, is not a refined oil, and as such contains significantly higher concentrations of squalene than refined olive oils or seed oils.³ (See Grades of Olive Oils infographic here). Squalene is in fact the major hydrocarbon present in Virgin Olive Oils, accounting for greater than 90% of the total hydrocarbon content of the oil.³

“Olive Oil contains up to 300-fold more squalene than other vegetable oils and up to 5,000-fold more than some vegetable foods”.³

As an ingredient, squalene can be found in a variety of cosmetic products around the world. It acts as an effective lubricant on the skin’s surface, giving the skin a soft and smooth appearance.⁴ Throughout the body, the highest levels of squalene can be found in the skin (approximately 12% versus 0.001–0.04% in the adipose tissue).¹ Human skin cells are the largest organ in the body, which are constantly exposed to stress such as Ultra-Violet (UV) light radiation.⁵ Skin cells are naturally rich in lipids which are prone to oxidative stress caused by UV light. Squalene is one of the lipids that is naturally found in human skin cells.⁵ The sebaceous glands under the skin surface release sebum (an oily secretion that lubricates the skin and hair) of which the predominant fraction (13%) is squalene.⁵ However, after the age of around 30 years, the levels of squalene production in the body reduce dramatically, which may contribute to dry skin conditions.⁶

Benefits of Squalene for Skin Health

Antioxidant Activity:

• Being a natural antioxidant compound, squalene plays a role to reduce free radical oxidative damage in the skin.
• UV light causes the formation of carcinogenic singlet oxygen species within the skin – squalene has been shown (in vitro) to have a strong ability to scavenge singlet oxygen species. (Epidemiological research suggests that populations who consume a Mediterranean style diet (with Extra Virgin Olive Oil as the predominant fat) have a lower incidence of skin cancer).¹
• Squalene has been shown in vitro to reduce the free radical superoxide anion which may cause skin irritation.⁷

Emollient

• Squalene is a natural emollient that is quickly and effectively absorbed deep into the skin – this helps to restore the skin suppleness and flexibility (and does not leave an oily residue).⁵

Hydration

• Preliminary in vitro evidence shows that squalene may assist with skin occlusion to reduce water loss and improve hydration.⁵
• Through better hydration, squalene may be able to reduce the signs of fine lines and wrinkles.⁷

Treatment of Skin Conditions

• Squalene may play a role in protecting against bacterial and fungal skin infections – this could be a possible application for patients with atopic dermatitis or acne.⁷

Favourable Properties

• As an additive in cosmeceutical preparations, squalene possesses chemical characteristics that could be advantageous, such as:⁷
  • Providing long term product physical and chemical stability
  • Improved penetration of active ingredients through the epidermis (possibly allowing for more rapid and profound action of locally applied medications).

Olive based squalene is a common alternative to shark derived squalene – a common cosmetic ingredient across the globe. From a topical perspective, squalene provides a variety of benefits for skin health, and is a favourable vehicle for skin-based preparations. There is limited evidence for the benefits of topical squalene in human trials, and this provides an excellent opportunity for researchers in the future.

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