Tuna oil is a marine oil obtained from tuna tissues and processing by-products. It is valued mainly for its long-chain omega-3 fatty acids, particularly EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Research on tuna-derived oils shows that their EPA and DHA concentrations can vary substantially depending on the tuna species, tissue used, extraction method, and purification process.
Because tuna is a large predatory fish, it is also important to distinguish tuna oil supplements from eating tuna meat. Purified commercial oils may undergo processing and testing for contaminants, while tuna itself can contain methylmercury.
What Is Tuna Oil?
Tuna oil is a type of fish oil derived from tuna. It is naturally rich in long-chain polyunsaturated fatty acids, especially EPA and DHA.
Unlike tuna meat, tuna oil contains little to no protein or carbohydrate and is primarily a concentrated source of fat. The exact EPA and DHA content differs among products. For example, one published analysis reported approximately 53 mg EPA and 241 mg DHA per gram of tuna oil, while other studies have found substantially different concentrations after processing and concentration.
Tuna oil is commonly sold in softgel capsules, liquid supplements, and specialized nutritional products. Some products are also formulated to reduce the characteristic fishy taste and odor.
Nutrition Facts of Tuna Oil
The nutritional composition varies by product, so the supplement label should be considered the most accurate source for EPA and DHA content.
| Nutrient | Approximate amount in 1 teaspoon (5 mL) of pure oil* |
|---|---|
| Calories | About 40 kcal |
| Total Fat | About 4.5 g |
| Protein | 0 g |
| Carbohydrates | 0 g |
| Fiber | 0 g |
| EPA | Variable |
| DHA | Variable |
| Omega-3 fatty acids | Variable |
| Cholesterol | May be present in small amounts depending on processing |
*Values are general estimates for fish oil rather than a standardized composition for every tuna oil product. EPA and DHA concentrations can differ considerably among tuna oils.
20 Proven Health Benefits of Tuna Oil
- Supports Heart Health: EPA and DHA contribute to cardiovascular health, while omega-3 supplementation can lower triglyceride levels, particularly at appropriately selected doses.
- Helps Maintain Healthy Triglycerides: Concentrated EPA and DHA can reduce blood triglyceride levels, although therapeutic doses should be used under professional guidance.
- Supports Brain Function: DHA is an important structural component of brain tissue and contributes to normal neurological function.
- Supports Eye Health: DHA is highly concentrated in the retina, where it contributes to the structure and function of retinal cells.
- Provides Essential Omega-3 Fatty Acids: Tuna oil supplies long-chain omega-3s that are difficult to obtain in concentrated amounts from many plant foods.
- Supports Normal Cell Membranes: EPA and DHA become incorporated into cell membranes and influence their structure and signaling.
- Supports Normal Inflammatory Regulation: Omega-3 fatty acids participate in biological pathways involved in the body’s inflammatory response.
- Supports Brain Development: DHA plays an important structural role during brain development, particularly during pregnancy and early life.
- Supports Visual Development: DHA contributes to normal development and maintenance of visual tissues.
- May Support Joint Comfort: Omega-3 fatty acids have been studied for their potential role in inflammatory joint conditions, although tuna oil should not be considered a treatment by itself.
- Supports Healthy Blood Lipids: Replacing some sources of saturated fat with unsaturated fats can contribute to a healthier overall dietary fat pattern.
- Supports Healthy Aging: Adequate omega-3 intake is being investigated for its role in maintaining cardiovascular, neurological, and visual health as people age.
- May Support Metabolic Health: EPA and DHA influence lipid metabolism and have been studied in people with metabolic risk factors.
- Supports Skin Barrier Function: Omega-3 fatty acids contribute to cell membranes and may help support normal skin barrier function as part of an overall balanced diet.
- Supports Hair and Scalp Nutrition: Adequate dietary fats, including omega-3s, contribute to overall nutritional support for healthy skin and hair.
- Supports Immune Function: Omega-3 fatty acids participate in immune-cell membrane structure and signaling.
- Provides a Concentrated Source of DHA: Certain tuna oils can contain substantial amounts of DHA, making them useful when a concentrated DHA source is desired.
- May Support Cardiovascular Risk Management: Research suggests omega-3 supplementation can influence certain cardiovascular risk markers, although results differ according to dose, population, and formulation.
- Supports Nutrient Intake When Fish Consumption Is Limited: A properly formulated supplement can provide EPA and DHA for people who do not regularly eat oily fish.
- Can Be a Sustainable By-Product Source: Some tuna oils are produced from fish-processing by-products, potentially making use of materials that would otherwise be discarded.
10 Side Effects of Tuna Oil
Most side effects associated with tuna oil are similar to those reported with other omega-3 supplements and are usually mild.
- Fishy Aftertaste: Tuna oil can leave an unpleasant fishy taste in the mouth, particularly with liquid products.
- Fishy Breath: Some people may notice fish-like breath after taking fish oil supplements.
- Heartburn: Tuna oil may cause reflux or heartburn in sensitive individuals.
- Nausea: Taking oil supplements on an empty stomach may cause nausea in some people.
- Stomach Discomfort: Mild abdominal discomfort can occur after taking concentrated fish oil.
- Diarrhea: Larger amounts of fish oil may loosen stools or cause diarrhea.
- Headache: Headache has been reported as an occasional side effect of omega-3 supplementation.
- Unpleasant Burping: Fishy burps are a common complaint with some fish-oil formulations.
- Increased Bleeding Risk at High Doses: High-dose omega-3 supplementation may affect platelet aggregation and requires additional caution with anticoagulant medicines.
- Possible Atrial Fibrillation Risk at High Doses: Some large trials have found a slight increase in atrial fibrillation among people taking 4 g/day of omega-3 supplements who already had cardiovascular disease or high cardiovascular risk.
How to Use Tuna Oil?
Tuna oil is generally used as a source of EPA and DHA rather than as a cooking oil.
You can use it in the following ways:
- Softgel Supplements: Swallow the recommended number of capsules with water.
- Liquid Tuna Oil: Measure the amount using the product’s supplied spoon or measuring device.
- With Meals: Taking tuna oil with a meal may improve tolerance and reduce fishy aftertaste.
- Food Fortification: Some specially formulated tuna oils can be incorporated into foods, but ordinary supplements should be used according to their label.
- Veterinary Products: Tuna or fish oils formulated specifically for pets may be used for animals, but human and animal products should not automatically be considered interchangeable.
Other Uses of Tuna Oil
Tuna oil has applications beyond ordinary dietary supplementation.
- It is used as a source of EPA and DHA in nutritional supplements.
- It can be incorporated into functional foods and beverages.
- It is used in research investigating concentrated DHA formulations.
- Tuna-processing by-products can be converted into omega-3-rich oils, supporting more efficient use of fish resources.
- Specialized tuna oils may be used in nutritional formulations for their DHA content.
Tips for Consuming Tuna Oil
- Check EPA and DHA: Look at the actual EPA and DHA amounts rather than judging a supplement only by the total amount of tuna oil.
- Choose Tested Products: Prefer products that provide information about quality testing and contaminant control.
- Start With the Label Dose: Do not automatically take large amounts simply because omega-3s are considered beneficial.
- Take It With Food: Taking tuna oil alongside a meal may reduce digestive discomfort and fishy burps.
- Check Freshness: Avoid products with a strongly rancid or unusually unpleasant odor.
- Read the Serving Size: One capsule can contain a very different amount of EPA and DHA from another product.
- Avoid Excessive Doses: More omega-3 is not necessarily better, and high doses should be medically supervised.
- Consider Your Total Omega-3 Intake: Include EPA and DHA obtained from fish, fortified foods, and other supplements when considering your overall intake.
- Store It Properly: Protect tuna oil from heat, light, and prolonged exposure to air.
- Ask About Interactions: Speak with a healthcare professional if you regularly take prescription medicines.
How to Take Tuna Oil?
Tuna oil can usually be taken with or immediately after a meal, especially if you experience fishy burps or stomach discomfort.
For capsules, swallow them with water and follow the manufacturer’s serving instructions. For liquid tuna oil, use the supplied measuring device rather than estimating the amount with an ordinary kitchen spoon.
The most important number to check on the label is the combined EPA + DHA per serving, because the total oil weight does not tell you how much omega-3 you are actually receiving.
How Much Tuna Oil Can You Take Per Day?
There is no single standard daily dose of tuna oil because products contain different amounts of EPA and DHA.
For general supplementation, follow the manufacturer’s recommended serving rather than choosing a dose based only on the volume of oil.
The NIH notes that the FDA considers supplements providing up to 5 g per day of combined EPA and DHA to be safe when used as recommended, but this does not mean that everyone should consume 5 g daily. Higher therapeutic doses should be used only with appropriate medical supervision.
Tuna Oil Dosage
| Purpose | Typical approach |
|---|---|
| General omega-3 supplementation | Follow the product’s EPA + DHA serving recommendation |
| Low dietary fish intake | Discuss an appropriate EPA/DHA dose with a healthcare professional |
| High triglycerides | Medical supervision is recommended because therapeutic doses may be much higher |
| Pregnancy | Use only a pregnancy-appropriate product and discuss dosage with a healthcare professional |
| Children | Use an age-appropriate product and professional guidance |
| Prescription omega-3 therapy | Follow the prescribed dose rather than an ordinary supplement label |
Important: Tuna oil dosage should be based primarily on EPA + DHA content, not simply the number of milligrams of oil.
Best Time to Take Tuna Oil
There is no universally established “best” time of day to take tuna oil.
Taking it with a meal is often practical because food may improve tolerance and reduce digestive complaints. If the daily amount is divided into multiple servings, taking the doses with different meals may also make supplementation easier to tolerate.
Consistency is generally more important than a particular morning or evening schedule.
Who Should Take Tuna Oil?
- Adults With Low Fish Intake: People who rarely eat oily fish may discuss an omega-3 supplement with a healthcare professional.
- People Seeking EPA and DHA: Tuna oil can provide concentrated marine omega-3 fatty acids.
- People With Elevated Triglycerides: Prescription-strength omega-3 treatment may be appropriate for some people, but this should be medically supervised.
- People Following Certain Dietary Patterns: Those who do not regularly consume seafood may consider a suitable omega-3 supplement after discussing their nutritional needs.
- Adults Interested in DHA: Tuna oil can be a concentrated source of DHA, depending on the product formulation.
Who Should Avoid Tuna Oil?
- People With Fish Allergy: Anyone with a known fish allergy should discuss the safety of tuna-derived products with a healthcare professional before using them.
- People Taking Blood Thinners: High-dose omega-3 supplements may interact with anticoagulant or antiplatelet medicines.
- People With Bleeding Disorders: Medical advice is appropriate before taking concentrated omega-3 supplements.
- People Preparing for Surgery: Tell your doctor about tuna oil and other supplements before an operation.
- People With Atrial Fibrillation: Those with existing cardiovascular conditions should discuss high-dose omega-3 supplementation with their healthcare professional because high doses have been associated with a small increased risk of atrial fibrillation in some trials.
- Pregnant or Breastfeeding Women: Choose supplements carefully and discuss the specific product and dose with a healthcare professional.
- Young Children: Children should not be given adult-strength tuna oil supplements unless specifically advised by a pediatric healthcare professional.
- People With Significant Digestive Sensitivity: Anyone who develops persistent nausea, diarrhea, or reflux should reconsider the product and dosage with a healthcare professional.
How to Store Tuna Oil?
Store tuna oil according to the manufacturer’s instructions. In general:
- Keep capsules or liquid oil away from direct sunlight.
- Store it in a cool, dry location.
- Close liquid bottles tightly after every use.
- Avoid leaving the bottle exposed to heat.
- Refrigerate liquid products if the label recommends it.
- Do not use oil that has developed a strong rancid odor or obvious deterioration.
- Check the expiration or best-before date before use.
Because tuna oil is rich in polyunsaturated fats, oxidation can affect its quality. Research on tuna oils has specifically examined oxidative stability and the effect of processing and storage on EPA and DHA.
Precautions and Interactions
- Anticoagulants: High-dose omega-3 supplements may increase bleeding concerns when combined with medicines such as warfarin, so medical advice is recommended.
- Antiplatelet Medicines: People taking medicines that reduce platelet activity should discuss concentrated omega-3 supplementation with their healthcare provider.
- Blood Pressure Medicines: Omega-3s can influence cardiovascular parameters, so people taking blood-pressure medication should discuss high-dose supplementation with their clinician.
- Surgery: Tell your surgeon or healthcare professional about tuna oil and other supplements before planned procedures.
- Fish Allergy: Tuna-derived products may not be appropriate for people with fish allergies.
- Pregnancy: Pregnancy requires careful selection of fish products because mercury exposure from seafood can be important; discuss supplements with a healthcare professional.
- Children: Children are more vulnerable to excessive methylmercury exposure, so seafood choices and supplements should be age-appropriate.
- High-Dose Omega-3: Do not assume that very high doses provide additional benefits; higher doses should have a specific medical reason.
- Atrial Fibrillation: People with cardiovascular disease or elevated cardiovascular risk should discuss high-dose omega-3 supplementation because some trials found a slight increase in atrial fibrillation with 4 g/day supplementation.
- Other Supplements: Tell your healthcare professional about all supplements you take so potential interactions and duplicated omega-3 intake can be assessed.
Tuna Oil vs Eating Tuna
Tuna and tuna oil are not nutritionally interchangeable.
Tuna provides protein, vitamins, minerals, and other nutrients, while tuna oil is primarily a concentrated source of fat and omega-3 fatty acids. Eating fish also requires consideration of species-specific mercury exposure. The FDA currently categorizes canned light tuna as a lower-mercury “Best Choice,” while albacore/white tuna and yellowfin are categorized differently, and bigeye tuna is in the “Choice to Avoid” category because of its higher mercury level.
Therefore, choosing tuna oil does not mean that someone should automatically stop eating fish, and eating tuna does not necessarily provide the same EPA/DHA concentration as a supplement.
Is Tuna Oil High in Mercury?
Mercury is an important consideration with tuna, but the mercury content of an oil supplement cannot be assumed from the mercury content of tuna meat.
Commercial supplements may undergo purification and quality testing, so consumers should look for products that provide information about contaminant testing and manufacturing standards. Methylmercury accumulates more in certain larger, longer-lived fish, which is one reason tuna species have different consumption recommendations.
Final Thoughts
Tuna oil is primarily valued as a source of EPA and DHA omega-3 fatty acids. Its potential role includes supporting cardiovascular, brain, eye, cell-membrane, and inflammatory health, but the strength of evidence varies by outcome, dose, and individual health status.
The most important factor when choosing a tuna oil supplement is not simply the amount of oil in each capsule. Instead, check the EPA + DHA content, product quality, purity testing, serving size, storage instructions, and expiration date.
For people taking medications, preparing for surgery, pregnant or breastfeeding, or considering high-dose omega-3 supplementation, professional guidance is particularly important.
FAQ’s
What is tuna oil made from?
Tuna oil is made by extracting and processing oil from tuna tissues, including certain fish-processing by-products, and it is naturally rich in omega-3 fatty acids such as EPA and DHA.
Is tuna oil the same as fish oil?
Tuna oil is a type of fish oil, but it specifically comes from tuna and may have a different EPA-to-DHA profile than oils derived from sardines, anchovies, salmon, or other fish.
What is tuna oil good for?
Tuna oil provides EPA and DHA, which support normal heart, brain, eye, cell-membrane, and inflammatory functions.
Does tuna oil contain omega-3?
Yes, tuna oil naturally contains long-chain omega-3 fatty acids, primarily EPA and DHA, although the amounts vary between products.
Can I take tuna oil every day?
Many people can take an appropriately formulated tuna oil supplement daily, but the suitable amount depends on the EPA and DHA content and your individual health needs.
Does tuna oil smell fishy?
Yes, tuna oil can have a mild fishy smell or taste, particularly when it is in liquid form or has been exposed to air for a long time.
Can tuna oil cause fishy burps?
Yes, fishy burps are a common side effect of some fish-oil supplements, and taking tuna oil with food may help reduce them.
Is tuna oil good for the heart?
EPA and DHA can help lower triglyceride levels, and omega-3 fatty acids play several roles in cardiovascular health, although supplementation is not appropriate for everyone.
Is tuna oil good for the brain?
DHA is an important structural component of brain tissue, so adequate DHA intake contributes to normal brain structure and function.
Is tuna oil good for the eyes?
DHA is highly concentrated in the retina and contributes to normal retinal structure and visual function.
Can tuna oil help with high triglycerides?
High-dose EPA/DHA products can lower triglyceride levels, but treatment-level doses should be taken under medical supervision rather than self-prescribed.
Is tuna oil safe during pregnancy?
Pregnant women should discuss any tuna oil supplement with their healthcare professional and choose products carefully, particularly because mercury exposure from seafood requires special consideration during pregnancy.
Can children take tuna oil?
Children should only take tuna oil supplements in an age-appropriate formulation and amount recommended by a pediatric healthcare professional.
Can tuna oil interact with blood thinners?
High doses of omega-3 supplements may require caution with anticoagulant and antiplatelet medicines, so people taking blood thinners should consult their healthcare professional.
Which is better, tuna oil or salmon oil?
Neither is universally better; the appropriate choice depends on the product’s EPA and DHA concentrations, quality testing, dietary needs, and individual health considerations.
Can tuna oil cause stomach problems?
Yes, some people may experience nausea, heartburn, abdominal discomfort, diarrhea, or fishy burps, particularly with larger amounts.
How long does it take for Tuna Oil to work?
There is no fixed time because results depend on the reason for taking it; changes in triglyceride levels may be seen over several weeks, while general nutritional benefits may not produce noticeable symptoms or sensations.
What does Tuna Oil smell like?
Tuna oil typically has a mild to moderate fishy or marine smell, although high-quality purified and properly stored products may have less odor.
Is Tuna Oil good for fishing?
Yes, tuna oil can be used as a fish attractant or scent additive because its strong marine odor can help attract certain fish, but its effectiveness varies by species, fishing conditions, and how it is applied.
What is tuna fish in oil used for?
Tuna fish packed in oil is mainly used as a convenient, protein-rich food for salads, sandwiches, pasta, wraps, casseroles, and other meals, while the oil adds flavor and increases the food’s calorie and fat content.
Is tuna better in oil or water?
Neither is universally better; tuna in water is generally lower in calories and fat, while tuna in oil is richer, more flavorful, and higher in calories, so the better choice depends on your dietary needs and preferences.
Sources / References:
About the Author:
Written by: Kirti Solanki (Health Content Researcher)
Kirti Solanki is a health content researcher focused on creating reader-friendly, evidence-informed content on nutrition, wellness, food ingredients, and healthy lifestyle topics. Her content is developed using reputable medical, government, and scientific sources to make complex health information easier to understand.
Medical Disclaimer:
This guide is for general educational purposes and does not replace medical advice, diagnosis, or treatment. Tuna oil and other omega-3 supplements may interact with medicines and may not be suitable for everyone. Consult a qualified healthcare professional before starting a concentrated supplement.
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