Shark liver oil has a long history of use as a dietary supplement and is particularly known as a natural source of squalene, a lipid that is also found naturally in the human body.
Search online for shark liver oil and you may come across a wide range of claims relating to cardiovascular health, immunity, ageing, weight management, skin health and even serious diseases.
However, not all of these claims are supported by sufficient scientific evidence, and research findings about individual compounds should not automatically be interpreted as proven benefits of commercially available shark liver oil supplements.
So what exactly is shark liver oil? What is squalene, and how is it different from squalane? What does current research actually tell us?
This guide takes a closer look at shark liver oil and its characteristic lipids, while separating established facts from areas that are still being investigated.
What is shark liver oil?
Shark liver oil is an oil obtained from the liver of certain species of shark. Oils derived from the livers of fish have historically been used as foods and nutritional supplements, although their composition varies considerably depending on the species, source and manufacturing process.
Some deep-sea sharks have relatively large, oil-rich livers. Unlike many bony fish, sharks do not have a swim bladder, and liver lipids contribute to buoyancy.
One of the compounds commonly associated with shark liver oil is squalene.
Shark liver oils may also contain other lipids, including alkylglycerols. However, it is important not to assume that every shark liver oil supplement contains the same compounds or the same amounts.
The composition of a finished supplement depends on the raw material and how the product has been formulated and processed.
What is squalene?
Squalene is a naturally occurring lipid found in both animals and plants. Although shark liver oil is one well-known source, squalene is not exclusive to sharks.
It can also be found in foods and plant oils such as olive oil, as well as in the human body.
In humans, squalene is an intermediate in the biochemical pathway used to produce cholesterol and other sterols.
This makes squalene an interesting compound from a biological perspective, and its metabolism, absorption and other properties have been investigated in a variety of scientific studies.
Squalene and squalane are not the same thing
The similar names can make squalene and squalane easy to confuse, but they are not exactly the same substance.
Squalene is an unsaturated lipid. Squalane is produced by hydrogenating squalene, which creates a more chemically stable compound that is less susceptible to oxidation.
Squalane is widely used in skincare and cosmetic formulations as an emollient that helps soften the skin and reduce moisture loss.
This distinction is particularly important when discussing beauty-related claims.
The properties of squalane when applied topically in a cosmetic product should not automatically be attributed to squalene when consumed orally as a dietary supplement.
For example, the fact that squalane is used in moisturising skincare does not establish that taking a squalene supplement will moisturise the skin or reduce wrinkles or pigmentation.
Does all shark liver oil contain DHA and EPA?
Shark liver oil is sometimes described as a source of DHA and EPA because these omega-3 fatty acids can occur in marine oils.
However, this does not mean that every shark liver oil supplement should be treated as a DHA or EPA supplement.
Commercial products can differ significantly in their composition. Some are formulated primarily around squalene, while conventional fish oil supplements are commonly formulated specifically to provide measurable amounts of DHA and EPA.
If DHA and EPA are your primary reason for choosing a supplement, a fish oil product specifically formulated around these omega-3 fatty acids may therefore be more relevant.
What about vitamin A and vitamin D?
Traditional fish liver oils are often associated with fat-soluble vitamins such as vitamins A and D. However, the vitamin content of shark liver oil products varies according to the source and processing method.
It is therefore not appropriate to assume that every shark liver oil supplement contains significant amounts of vitamins A or D simply because it is made from liver oil.
This distinction is also important when discussing excessive vitamin A intake. High intakes of preformed vitamin A can be harmful, but this does not mean that every squalene-focused shark liver oil supplement contains high levels of vitamin A.
Rather than treating all shark liver oil products as nutritionally identical, it is more useful to understand what the individual product has been designed to provide.
Why is shark liver oil of interest?
A natural question is: if shark liver oil is not a medicine, why have people taken an interest in it as a dietary supplement?
One of the main reasons is its characteristic lipid composition, particularly squalene.
Squalene occurs naturally in the human body and participates in the biosynthetic pathway that produces cholesterol and other sterols.
Squalene and other lipids associated with shark liver oil have also been investigated from several scientific perspectives, including their relationship with oxidation and lipid metabolism.
Alkylglycerols found in some shark liver oils have also been studied in relation to biological processes associated with immune and inflammatory responses.
These characteristics have contributed to the long-standing interest in shark liver oil as a dietary supplement for people who take an active interest in their everyday nutrition and wellbeing.
However, this should not be interpreted to mean that taking shark liver oil prevents disease or treats a particular medical condition. The nutritional characteristics of a food or supplement and the therapeutic effects of a medicine are different matters.
What does research tell us about squalene?
Squalene has been investigated for many years because of its biological role and distinctive chemical properties.
As a naturally occurring lipid in the human body, it forms part of the pathway through which cholesterol and other sterols are synthesised. Researchers have also investigated how dietary squalene is absorbed and metabolised.
Squalene and antioxidant-related research
One area of scientific interest concerns squalene and oxidation.
Research has examined antioxidant-related properties of squalene as well as its metabolism and biological functions.
However, the word “antioxidant” should be interpreted carefully. Evidence of antioxidant-related properties under particular experimental conditions does not automatically establish that consuming squalene prevents ageing, cancer, cardiovascular disease or other health conditions.
Laboratory findings and health outcomes in people are not interchangeable.
Nevertheless, the behaviour of squalene in biological systems and its potential relationship with oxidative processes remain areas of scientific interest.
Research into shark liver oil and lipid metabolism
Researchers have also investigated shark liver oil and its characteristic lipids in relation to lipid metabolism.
A randomised, double-blind, placebo-controlled crossover study published in 2021 examined the effects of purified shark liver oil supplementation in 10 overweight or obese men.
The researchers reported changes in several circulating lipids and biomarkers, including an increase in certain ether lipids such as plasmalogens, alongside changes in triglycerides, free cholesterol and C-reactive protein.
Reference: Shark liver oil supplementation enriches endogenous plasmalogens and reduces markers of dyslipidemia and inflammation (PubMed)
This is an interesting study when considering how characteristic lipids from shark liver oil may be processed in the body.
However, it was a small, short-term study involving only 10 participants. The purified shark liver oil, dosage and study conditions should also not be assumed to be equivalent to those of commercially available supplements.
The results therefore do not establish that shark liver oil supplements lower cholesterol or triglycerides, or that they prevent or treat cardiovascular or metabolic disease.
Research into alkylglycerols
Another area of shark liver oil research concerns alkylglycerols, a group of ether lipids found in some shark liver oils.
Researchers have investigated alkylglycerols in relation to several biological processes, including responses associated with inflammation and immune function.
A randomised crossover study involving adults with obesity, for example, examined the relationship between alkylglycerol supplementation and several circulating biomarkers associated with inflammatory and metabolic processes.
Reference: Alkylglycerols reduce serum complement and plasma vascular endothelial growth factor in obese individuals (PubMed)
A 2026 scoping review has also examined the existing body of research into shark liver oil and its components in relation to immune and inflammatory responses.
The review highlights areas of scientific interest while also noting substantial differences between studies and the need for further well-designed and standardised research.
Reference: Immunomodulatory and Anti-Inflammatory Potential of Shark Liver Oil: A Scoping Review of Human and Animal Studies (PubMed)
In other words, these compounds are not scientifically unexplored. At the same time, the available evidence does not establish shark liver oil supplements as treatments or preventive measures for specific diseases.
Why scientific studies should be interpreted carefully
Statements such as “scientifically studied” or “supported by research” are common in discussions about nutritional supplements.
Scientific research is valuable, but the existence of a study does not automatically prove that a commercially available supplement provides the same outcome.
Clinical and laboratory studies may use purified ingredients, different doses, specific groups of participants or treatment periods that are very different from everyday supplement use.
The studies referenced in this article are provided to help explain the scientific research surrounding shark liver oil and its components.
They do not demonstrate that shark liver oil supplements sold by Brilliant Life Products NZ prevent, diagnose, treat or improve any disease or medical condition.
Understanding both what research suggests and what has not yet been established is an important part of making informed decisions about dietary supplements.
What about shark liver oil for skin and beauty?
Shark liver oil and squalene are also frequently discussed in connection with beauty and skincare.
This is where the distinction between squalene and squalane becomes particularly important.
Squalane is widely used in cosmetic products as an emollient. Applied topically, it can help soften the skin and reduce moisture loss.
Orally consuming squalene as part of a dietary supplement is a different form of use.
It would therefore be inappropriate to take the moisturising properties of topical squalane and conclude that consuming squalene will moisturise the skin, eliminate pigmentation, prevent acne or reduce wrinkles.
Topical squalane and dietary squalene should be considered according to their respective uses.
What to know when considering a shark liver oil supplement
When considering shark liver oil, one useful starting point is understanding which component the supplement is primarily designed to provide.
Products described as shark liver oil can have different formulations. Some focus on squalene, while others may have different lipid profiles or combinations of ingredients.
A squalene-focused shark liver oil supplement
The Health Life New Zealand Shark Liver Oil (Squalene) 300 Capsules available from Brilliant Life Products NZ provides 500 mg of squalene per capsule.
It also contains vitamin E and has a relatively simple formulation centred on squalene.
This makes the amount of squalene supplied by each capsule straightforward for people who are specifically interested in adding squalene to their daily dietary routine.
Importantly, 500 mg should not be interpreted as meaning that the product is “more effective” or produces a stronger health effect. The quantity simply helps describe how the supplement has been formulated.
One option for an everyday wellness routine
Shark liver oil and squalene are not substitutes for medical treatment.
The foundations of good health remain a balanced diet, regular physical activity, adequate sleep and rest, and appropriate medical care when needed.
Within that broader context, a squalene-focused shark liver oil supplement can be one dietary option for people interested in incorporating this characteristic lipid into their everyday nutrition and wellness routine.
Practical considerations such as simplicity and ease of incorporating a supplement into your routine can also be useful when choosing a product for ongoing use.
Is shark liver oil safe?
Shark liver oil is used as a dietary supplement, but being a food or supplement does not mean that consuming more is necessarily better.
There is also no reason to assume that normal supplement use should automatically be a cause for concern. A sensible approach is to follow the recommended intake provided for the individual product.
Human studies involving shark liver oil and its components have used different formulations and doses, some of which may differ considerably from commercially available supplements.
For this reason, increasing the amount simply because an ingredient is perceived as beneficial is not advisable.
Individual responses to foods and supplements can also vary. If you experience an unexpected reaction after taking a supplement, discontinue use and seek advice from an appropriate healthcare professional when necessary.
People who have a medical condition, take medication, are pregnant or breastfeeding, or have concerns about whether a supplement is suitable for them should consult a doctor, pharmacist or other qualified healthcare professional before use.
Shark liver oil or fish oil?
Shark liver oil and conventional fish oil are both marine-derived oils, but supplements made from them often focus on different components.
Conventional fish oil supplements commonly focus on the omega-3 fatty acids DHA and EPA.
Shark liver oil supplements, on the other hand, may focus on characteristic lipids such as squalene or alkylglycerols.
Rather than asking which one is universally “better”, it is more useful to consider which type of nutrient or lipid you are interested in incorporating into your diet.
Summary: understanding shark liver oil and squalene
Shark liver oil is obtained from the liver of sharks and is particularly well known as a source of characteristic lipids such as squalene.
Squalene is a naturally occurring lipid that is also present in the human body and participates in the biosynthetic pathway used to produce cholesterol and other sterols.
Squalene has been studied from a number of perspectives, including its metabolism and antioxidant-related properties. Other components found in some shark liver oils, such as alkylglycerols, have also been investigated in relation to biological processes associated with immune and inflammatory responses.
This scientific research is valuable for understanding these compounds, but it does not establish commercially available shark liver oil supplements as treatments or preventive measures for specific diseases.
At the same time, shark liver oil remains a dietary source of distinctive lipids such as squalene and can be considered one option for people who wish to incorporate squalene into an everyday nutrition and wellness routine.
The Health Life New Zealand Shark Liver Oil (Squalene) 300 Capsules available from Brilliant Life Products NZ provides 500 mg of squalene per capsule in a simple, squalene-focused formulation with vitamin E.
As with any dietary supplement, shark liver oil is best considered as a complement to — rather than a replacement for — a balanced diet and healthy lifestyle.
Disclaimer: This article is intended to provide general educational information about shark liver oil, squalene, alkylglycerols and publicly available scientific research. It is not intended to diagnose, treat, cure or prevent any disease. The studies referenced in this article do not demonstrate that any specific dietary supplement sold by Brilliant Life Products NZ has therapeutic or disease-preventive effects. Ingredients, doses, study populations and study conditions may differ from commercially available products. If you have a medical condition, take medication, are pregnant or breastfeeding, or have concerns about your health or the suitability of a supplement, please consult a doctor, pharmacist or other qualified healthcare professional.
