Benefits of Squalene: From Deep Sea Sharks to Skincare

Squalene is one of the most valuable compounds extracted from the liver oil of deep-sea sharks. With the chemical formula C₃₀H₅₀, this highly unsaturated hydrocarbon belongs to the triterpene family and plays a significant role across the health, skincare, and pharmaceutical industries. From helping manage cholesterol to keeping skin youthful and hydrated, squalene has earned its reputation as a versatile fish by-product. But its high reactivity also makes it tricky to extract and store. Let’s break down everything you need to know about squalene – where it comes from, what it does, and why it matters.

What exactly is squalene? 🔗

Squalene is a naturally occurring lipid – a colourless, oily hydrocarbon that was first isolated from shark liver oil in the early 1900s by Japanese chemist Dr. Mitsumaro Tsujimoto. The name itself comes from Squalus, a genus of sharks. In the human body, squalene is produced naturally and constitutes roughly 12% of the sebum that lubricates and protects the skin. It is also a biochemical precursor in the synthesis of cholesterol, steroid hormones, and vitamin D.

While squalene is found in small amounts in plant sources like olive oil, amaranth seeds, rice bran, and wheat germ, the richest natural source remains the liver of deep-sea sharks. In certain species, squalene can constitute up to 90% of the liver oil, and the liver itself can account for 5-10% of the shark’s total body weight. This extraordinary concentration is the primary reason sharks have been commercially targeted for squalene extraction for decades.

Why do deep-sea sharks have so much squalene? 🔗

Unlike bony fish, sharks do not possess swim bladders to regulate their buoyancy. Instead, they rely on their large, oil-rich livers to stay afloat. Deep-sea sharks, in particular, have especially oily livers because they inhabit depths of 300 to 1,500 metres, where pressure is extreme. The squalene in their livers is less dense than water, giving these sharks a form of natural buoyancy control without expending extra energy.

Some cold-water deep-sea species can have livers containing 40-70% squalene by weight. In Centrophorus species (gulper sharks), squalene can represent as much as 15% of the shark’s total body weight. This biological adaptation makes deep-sea sharks the most commercially targeted source for squalene extraction.

Extraction of squalene from shark liver oil 🔗

Getting pure squalene out of shark liver oil is not straightforward. Because squalene is highly unsaturated – it has six double bonds in its molecular chain – it is extremely reactive and prone to oxidation. This means the extraction process requires careful handling to preserve the compound’s beneficial properties.

Molecular distillation 🔗

The most common method used is molecular distillation. In this process, shark liver oil is heated under reduced pressure (a vacuum), which allows squalene to evaporate at a lower temperature than it normally would. The vapour is then condensed to yield a relatively pure form of squalene. According to research published in Industrial & Engineering Chemistry Research, shark liver oil can contain approximately 50% squalene by weight, with the remainder being triglycerides and other components.

Supercritical carbon dioxide extraction 🔗

A more advanced technique involves using supercritical carbon dioxide (CO₂) as a solvent. In this method, CO₂ is brought to a state where it behaves like both a liquid and a gas, allowing it to selectively dissolve squalene from the liver oil. This approach produces high-purity squalene without the use of harsh chemical solvents and is considered more environmentally friendly.

Storage considerations 🔗

Once extracted, squalene must be stored carefully. Exposure to air, light, or heat can trigger rapid oxidation, degrading the compound and diminishing its useful properties. Squalene is typically stored in dark, airtight containers kept in cool, dry conditions. Antioxidants such as vitamin E are often added to squalene products to slow oxidation and extend shelf life. Even with these precautions, squalene has a limited shelf life of roughly two years.

Health benefits of squalene 🔗

Squalene has attracted significant scientific attention for its range of potential health benefits. While more human clinical trials are needed, existing research paints a promising picture.

Cholesterol management 🔗

One of squalene’s most studied effects is its influence on blood cholesterol. A systematic review published in the journal Nutrients found that squalene may help lower cholesterol by inhibiting HMG-CoA reductase, the same enzyme targeted by statin drugs. In animal studies, dietary squalene supplementation has been shown to reduce both total cholesterol and triglyceride levels. A study in PLOS ONE demonstrated that squalene increased HDL (“good”) cholesterol levels and boosted the antioxidant enzyme paraoxonase 1 in mice, suggesting a protective role for cardiovascular health.

In human studies, some controlled trials have reported that daily squalene supplementation (around 860 mg per day over 20 weeks) led to noticeable decreases in total and LDL cholesterol compared to placebo groups. However, results across studies have been mixed, and researchers recommend further controlled human trials for definitive conclusions.

Antioxidant and anti-aging properties 🔗

Squalene’s molecular structure – rich in double bonds – gives it strong antioxidant capabilities. It acts as an effective scavenger of reactive oxygen species (ROS), which are unstable molecules that cause cellular damage and contribute to aging. According to a review in Molecular Nutrition & Food Research, squalene accumulates in the liver and decreases hepatic cholesterol and triglycerides through complex changes in gene expression. Its combination with other bioactive compounds can enhance these protective properties, potentially helping manage oxidative stress-related age-related diseases.

In the skin, squalene functions as a quencher of singlet oxygen – a particularly harmful form of oxygen generated by UV exposure. This protective function helps prevent lipid peroxidation at the skin’s surface, reducing the kind of oxidative damage that accelerates visible aging.

Immune system support 🔗

Squalene also plays a role in immune function. Research published in PubMed indicates that squalene supplementation in mice resulted in significant dose-dependent increases in both cellular and non-specific immune responses. Squalene is also used as a key ingredient in certain vaccine adjuvants – substances that enhance the body’s immune response to a vaccine. The adjuvant MF59, which contains squalene, has been used in influenza vaccines administered to over 22 million people in Europe since 1997.

Anti-inflammatory effects 🔗

Squalene has demonstrated anti-inflammatory activity in several studies. It appears to modulate the behaviour of immune cells at wound healing sites, promoting the activity of M2 macrophages – cells that help resolve inflammation and support tissue repair. According to ScienceDirect research overviews, squalene can modulate pro-inflammatory signals and prevent overactivation of neutrophils and monocytes, helping to efficiently control the inflammatory response.

Squalene in skincare and cosmetics 🔗

The skincare industry is by far the largest consumer of squalene. The compound’s natural compatibility with human skin makes it an exceptionally effective cosmetic ingredient.

How squalene works on skin 🔗

Since squalene is naturally present in human sebum, topical application essentially mimics and supplements the skin’s own moisturising system. As we age, our body’s squalene production declines – peak production occurs during the teen years and begins to drop in the 20s and 30s. This decline contributes to drier, rougher skin over time.

Applied topically, squalene (usually in its stabilised form, squalane) absorbs quickly and deeply into the skin without leaving an oily residue. It helps restore the skin’s lipid barrier, prevents transepidermal water loss, and improves elasticity. A review in the journal Molecules confirmed that squalene is a highly effective oxygen-scavenging agent that protects the skin surface from UV-induced lipid peroxidation.

Common cosmetic applications 🔗

Squalene and its hydrogenated derivative squalane are found in a wide range of products: sunscreens, anti-aging creams, face moisturisers, lip balms, lipstick, eye makeup, foundations, hair conditioners, and tanning oils. The compound improves the spreadability and absorption of creams and lotions, which is why it is so popular in high-end facial skincare formulations.

Squalene vs. squalane – what’s the difference? 🔗

This is a common point of confusion. Squalene (with an “e”) is the natural, unsaturated form. Because it oxidises rapidly when exposed to air, it cannot be used directly in skincare products. Through a process called hydrogenation, squalene is converted into squalane (with an “a”) – a saturated, stable form that retains the moisturising and emollient properties without the risk of going rancid. Chemically, squalane behaves the same whether it originates from shark or plant sources.

Squalene as a dietary supplement 🔗

Squalene supplements, usually in the form of shark liver oil capsules, are consumed for their potential cardiovascular, antioxidant, and immune-boosting benefits. Typical dosages in supplements range from 500 to 1,000 mg per day for cholesterol management purposes.

Some supplement users also report benefits like improved energy levels (squalene assists in cellular oxygen transport and respiration) and relief from joint inflammation. However, it is worth noting that not all of these claims have been validated through rigorous human clinical trials. Consumers should also be aware that some shark liver oil supplements have been found to contain environmental contaminants such as PCBs (polychlorinated biphenyls), which can pose health risks.

Conservation concerns and ethical sourcing 🔗

The commercial demand for squalene has raised serious environmental concerns. According to Oceana, deep-sea sharks targeted for their liver oil are slow-growing and reproduce late in life, making them particularly vulnerable to overexploitation. The cosmetics industry alone accounts for an estimated 90% of global shark liver oil demand, contributing to approximately 2.7 million deep-sea shark deaths annually.

Many of the targeted species, including various gulper sharks, appear on the IUCN Red List as endangered or vulnerable. The practice known as “shark livering” – where only the liver is removed and the rest of the carcass is discarded – mirrors the destructive practice of shark finning and has drawn widespread criticism from conservation organisations.

Plant-based and synthetic alternatives 🔗

Fortunately, alternatives exist. Squalene can be extracted from olive oil, sugarcane, amaranth seeds, rice bran, and wheat germ. Plant-derived squalene typically costs about 30% more than shark-derived squalene, which has historically slowed its adoption. However, the market has shifted significantly in recent years as consumer awareness has grown. Major cosmetic brands now increasingly source plant-derived or synthetic squalane. Genetically engineered yeast and bacteria can also produce squalene biosynthetically, offering another sustainable path forward.

Organisations like Shark Stewards and Oceana have campaigned successfully to push brands away from shark-derived squalene. Several companies, including Unilever, have committed to discontinuing its use.

Key properties of squalene at a glance 🔗

Chemical formula: C₃₀H₅₀
Type: Triterpene (highly unsaturated hydrocarbon)
Appearance: Colourless oil (yellow when impure)
Primary natural source: Deep-sea shark liver oil (up to 90% of the oil)
Plant sources: Olive oil, amaranth seed, sugarcane, rice bran, wheat germ
Skin presence: ~12% of human sebum
Key properties: Emollient, antioxidant, anti-inflammatory, moisturising, oxygen-scavenging
Stability: Highly prone to oxidation; must be stored in airtight, dark, cool conditions
Stabilised form: Squalane (hydrogenated squalene, used in skincare products)

The future of squalene 🔗

Squalene sits at an interesting crossroads. Its biological benefits – for cardiovascular health, skin protection, immune function, and more – are well-supported by growing scientific evidence. At the same time, the environmental cost of shark-derived squalene is unsustainable. The good news is that plant-based and biosynthetic alternatives are becoming more accessible and cost-effective every year.

As the nutraceutical and cosmetic industries continue to grow, sustainable sourcing of squalene will become even more critical. Consumers can play a role by choosing products labelled as using 100% plant-derived squalane and supporting brands that have committed to shark-free supply chains.

What do you think? Given the availability of plant-based alternatives, should the industry move toward a complete ban on shark-derived squalene? And if you use skincare products, have you ever checked whether the squalane in them comes from sharks or plants?

References

1. https://en.wikipedia.org/wiki/Squalene
2. https://pmc.ncbi.nlm.nih.gov/articles/PMC6253993/
3. https://en.wikipedia.org/wiki/Shark_liver_oil
4. https://usa.oceana.org/shark-squalene/
5. https://pubs.acs.org/doi/abs/10.1021/ie9702237
6. https://pmc.ncbi.nlm.nih.gov/articles/PMC7071298/
7. https://pmc.ncbi.nlm.nih.gov/articles/PMC4130590/
8. https://pubmed.ncbi.nlm.nih.gov/29883523/
9. https://pubmed.ncbi.nlm.nih.gov/9988781/
10. https://www.sciencedirect.com/topics/nursing-and-health-professions/squalene
11. https://sharkstewards.org/about-sharkstewards/what-we-do/shark-squalene/